aggress

[uh-gres] /əˈgrɛs/
verb (used without object)
1.
to commit the first act of hostility or offense; attack first.
2.
to begin to quarrel.
verb (used with object)
3.
to behave aggressively toward; attack (often followed by upon):
wild animals aggressing their prey.
Origin
1565-75; < Latin aggressus (past participle of aggredī to attack), equivalent to ag- ag- + gred- (see grade) + -tus past participle suffix
British Dictionary definitions for aggress

aggress

/əˈɡrɛs/
verb
1.
(intransitive) to attack first or begin a quarrel
Word Origin
C16: from Medieval Latin aggressāre to attack, from Latin aggredī to attack, approach
Word Origin and History for aggress
v.

"attack," 1714, back-formation from aggression, but used earlier with a sense of "approach" (1570s) and in this sense from French aggresser, from Late Latin aggressare, frequentative of Latin aggredi "to approach, attack." Related: Aggressed; aggressing.