突っ込む
つっこむ · tsukkomu · JLPT N2 · verb-godan
to plunge into
📌 突 (thrust, poke) + 込む (go or push inward) = thrust inward = plunge into
突く means to poke or thrust, and 込む means to go or push inward. Together they describe jabbing something deep into a place, the way a pin is pushed into cloth.