prod, nudge / prick, stab / bump into, collide / stick out, protrude / suddenly, abruptly, unexpectedly / (martial arts) an attacking move in kendo, sumo, et al.; thrust, lunge

collision, crash / conflict of opinion

collision, clash

crash into

charge

to charge (to attack by moving forward quickly)

rear end collision

run into from behind

convex area

(Internet slang) a meeting or encounter in real life (as opposed to online meetings)