突っ込む

to thrust (something) into (something); to cram; to stuff; to shove

to plunge into; to charge into; to rush into; to ram into; to crash into

to delve into (a matter); to go into depth; to get to the heart (of something)

to press (someone) about; to point out (e.g. an inconsistency); to question sharply; to grill

to get involved with; to meddle in; to poke one's nose into

to riposte; to retort; to quip