arm

ARM = Weapon

to arm: give weapons to

arms: weapons

armament: a collection of weapons

armour: something you wear to protect you from weapons 

ag

to go or move forward

synagogue

agitate

ven

to go  

venue

venture

advent

adventure

provenance

take back

intractable

retract

protract

detract

lev

lightweight

levitate

alleviate

levity

elevate

throw out

trajectory

eject

adjacent

conjecture

dejected

make happen

induction

induce

seduction

deduction

conducive

same

homeostatsis

homophone

homologous

homozygous

homogeneous

homocentric

near

epicenter

epithet

epitaph

epiphyte

down

catalogue

catapult

catatonic

catalyst

cataclysm

basic

protagonist

protoplasm

protozoa

proton

protoplanet

prototype

protocal

hear

auditor

audio

audience

auditorium

audition

son

hear

sonic

ultrasound

dissonant

sonorous

resonance

move/stray

erroneous

erratic

errant

error

aberrant

errand