quick, keen, or accurate knowledge or insight

1531, from L. acumen "a point, sting," hence "sharpness, shrewdness," from acuere "to sharpen" (see acuity).

shares root with acute (sharp) 

to reduce purity by combining with inferior ingredients

shares root with alter 

to disguise or conceal; to mislead

shares root with simulate, meaning "to create a likeness of"... so this means the opposite.  it is the antonym of resemble. 

departing from norms or conventions

1350–1400; < ML eccentricus < Gk ékkentr(os) out of center (see ec-, center ) + L -icus -ic 

characteristic of or often found in a particular locality, region, or people

A disease that occurs regularly in a particular area, as malaria does in many tropical countries, is said to be endemic. The word endemic, built from the prefix en-, "in or within," and the Greek word demos, "people," means "within the people (of a region)." A disease that affects many more people than usual in a particular area or that spreads into regions in which it does not usually occur is said to be epidemic. This word, built from the prefix epi-, meaning "upon," and demos, means "upon the people." In order for a disease to become epidemic it must be highly contagious, that is, easily spread through a population. Influenza has been the cause of many epidemics throughout history. Epidemics of waterborne diseases such as cholera often occur after natural disasters such as earthquakes and severe storms that disrupt or destroy sanitation systems and supplies of fresh water. 

tending to disappear like vapor; vanishing

shares root with vanish 

to make worse or more severe

shares root with acerbic, meaning "bitter"... this mean "to make more bitter" 

pompous speech or expression

1589, from L. grandiloquentia, from grandiloquus "using lofty speech," from grandis "big" + -loquus "speaking," from loqui "speak." 

rendered trite or commonplace by frequent usage

c.1700, originally, "person hired to do routine work," short for hackney "an ordinary horse" (c.1300), probably from place name Hackney (Middlesex), from O.E. Hacan ieg "Haca's Isle" (or possibly "Hook Island"). Now well within London, it was once pastoral. Apparently nags were raised on the pastureland there in early medieval times and taken to Smithfield horse market (cf. Fr. haquenée "ambling nag," an Eng. loan-word). Extended sense of "horse for hire" (1393) led naturally to "broken-down nag," and also "prostitute" (1579) and "drudge" (1546). Special sense of "one who writes anything for hire" led to hackneyed "trite" (1749); hack writer is first recorded 1826, though hackney writer is at least 50 years earlier. 

devotion to pleasurable pursuits, esp. to the pleasures of the senses

1855–60; < Gk hēdon() pleasure + -ism 

the consistent dominance of one state of ideology over others

1567, from Gk. hegemonia "leadership," from hegemon "leader," from hegeisthai "to lead." Originally of predominance of one city state or another in Gk. history. 

one who attacks or undermines traditional conventions or institutions

"breaker or destroyer of images," 1596, from Fr. iconoclaste, from M.L. iconoclastes, from Late Gk. eikonoklastes, from eikon (gen. eikonos) "image" + klastes "breaker," from klas- pt. stem of klan "to break." Originally those in the Eastern Church in 8c. and 9c. whose mobs of followers destroyed icons and other religious objects on the grounds that they were idols. Applied to 16c.-17c. Protestants in Netherlands who vandalized former Catholic churches on similar grounds. Extended sense of "one who attacks orthodox beliefs or institutions" is first attested 1842. Iconoclasm in this sense is from 1858. 

revealing no emotion

refers to "emotional passivity" 

immunity from punishment or penalty

Similar Sounding Synonym: Immunity

Shares root with punish 

in an initial stage; not fully formed

1525–35; < L inchoātus, var. of incohātus ptp. of incohāre to begin, start work on, perh. equiv. to in- -in-2 + coh(um) hollow of a yoke into which the pole is fitted + -ātus -ate 1 

unfortunate; inappropriate

felicity means "well-suited" 

without taste or flavor; lacking in spirit; bland

1620, "without taste or perceptible flavor," from Fr. insipide, from L.L. inspidus "tasteless," from L. in- "not" + sapidus "tasty," from sapere "have a taste" (also "be wise"). Fig. meaning "uninteresting, dull" first recorded 1649, but it was also a secondary sense in M.L.

shares root with sage, meaning "have a taste"... which is where the name for the spice came from. 

having or showing often vicious ill will, spite, or hatred

1500–10; < L malevolent- (s. of malevolēns) ill-disposed, spiteful, equiv. to male- male- + volent- (s. of volēns), prp. of velle to want, wish for, desire (see will 1 , -ent ) 

one who hates all other humans

"one who hates mankind," 1563, from Gk. misanthropos "hating mankind," from misein "to hate" + anthropos "man." Alternate form misanthropist is attested from 1656. 

to make or become less severe or intense; to moderate

1432, from L. mitigatus, pp. of mitigare "make mild or gentle," ult. from mitis "gentle, soft" + root of agere "do, make, act" (see act). First element is from PIE base *mei- "soft, mild." Mitigation is attested from 1362.

Similar Sounding Synonym: Moderate 

to obstruct or block

shares root with close, which is still a synonym 

the art or profession of training, teaching, or instructing

"pedagogue" means teacher...

1387, "schoolmaster, teacher," from O.Fr. pedagogue "teacher of children," from L. paedagogus "slave who escorted children to school and generally supervised them," later "a teacher," from Gk. paidagogos, from pais (gen. paidos) "child" + agogos "leader," from agein "to lead" (see act). Hostile implications in the word are at least from the time of Pepys. Pedagogy is 1583 from M.Fr. pédagogie, from Gk. paidagogia "education, attendance on children," from paidagogos "teacher." 

poverty; destitution

shares root with penurious (meaning "penny-pinching") 

to yearn intensely; to languish; to lose vigor

shares root with pain. 

the essential or central part

shares root with pit... as in the seed or "heart" of a fruit... evolved to mean to mean the "heart" of anything... 

precise and brief

"gets to the pith (central idea) of the issue" 

to appease; to calm by making concessions

1670–80; < L plācātus ptp. of plācāre to quiet, calm, appease, akin to placēre to please; see -ate 1

Similar Sounding Synonym: Pacify

think of placid, meaning "calm" 

a superficial remark, esp. one offered as meaningful

shares root with plate, and both share a root with the word flat... so this is meant as a "flat statement". 

given or coming forth abundantly; extravagant

1432, from L. profusus "spread out, lavish, extravagant," lit. "poured forth," prop. pp. of profundere "pour forth," from pro- "forth" + fundere "to pour" (see found (2)). Profusion is first attested 1545, from L. profusionem (nom. profusio) "a pouring out," from profusus. 

to grow or increase swiftly and abundantly

shares root with prolific, meaning "productive" 

prone to complaining or grumbling; quarrelsome

shares root with quarrelsome, which is still a similar sounding synonym 

obstinately defiant of authority; difficult to manage

Similar Sounding Synonyms: Rebellious, Refractory, Resistant 

to refuse to have anything to do with; disown

1545, "to cast off by divorce," from adj. meaning "divorced, rejected, condemned" (1464), from L. repudiatus, pp. of repudiare "to divorce or reject," from repudium "divorce, rejection," from re- "back, away" + pudium, probably related to pes-/ped- "foot." The original notion may be of kicking something away, but folk etymology commonly connects it with pudere "cause shame to." Of opinions, conduct, etc., attested from 1824.

Similar Sounding Synonym: Reject 

to invalidate; to repeal; to retract

Similar Sounding Synonym: Retract 

marked by, feeling, or expressing a feeling of profound awe and respect

Similar Sounding Synonym: Respectful

Is akin to revere 

seeming true, but actually being fallacious; misleadingly attractive

c.1400, "pleasing to the sight, fair," from L. speciosus "good-looking, beautiful," from species "appearance" (see species). Meaning "seemingly desirable, reasonable or probable, but not really so" is first recorded 1612. 

lacking authenticity or validity; false; counterfeit

1598, "born out of wedlock," from L. spurius "illegitimate, false" (cf. It. spurio, Sp. espurio), from spurius (n.) "illegitimate child," probably from Etruscan spural "public." Sense of "having an irregular origin, not properly constituted" is from 1601; that of "false, sham" is from 1615. 

excess; overindulgence

c.1300, from O.Fr. surfet "excess," noun use of pp. of surfaire "overdo," from sur- "over" + faire "do," from L. facere "to make" (see factitious). The verb is first recorded 1393. 

the quality of adherence or persistence to something valued

1526, from M.Fr. ténacité (14c.), from L. tenacitas "the act of holding fast," from tenax (gen. tenacis) "tough, holding fast," from tenere "to hold" (see tenet). Tenacious first attested 1607.

good synonym: perseverence 

having little substance or strength; flimsy; weak

presumably shares heritage with the root tener, meaning "to hold"... this would then mean "incapable of holding" 

fleeting; passing quickly; brief

Similar Sounding Synonym: Transitionary