to commit the first act of hostility or offense; attack first.
to begin to quarrel.
verb (used with object)
to behave aggressively toward; attack (often followed by upon): wild animals aggressing their prey.
verb
(intr) to attack first or begin a quarrel
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.