1To thrust, shove, or cram something forcefully into a space (e.g., a bag, pocket, outlet).
出かける前に、財布とスマホをかばんに突っ込んだ。
Before heading out, I stuffed my wallet and phone into my bag.
プラグをコンセントに突っ込んだが、電気がつかなかった。
I plugged the cord into the outlet, but the light didn't come on.
洗濯物を洗濯機に突っ込んで、スイッチを押した。
I shoved the laundry into the washing machine and hit the switch.
ポケットに手を突っ込んで歩いていたら、先生に注意された。
I was walking with my hands shoved in my pockets, and the teacher scolded me.
2To plunge, rush, or charge into something; also used when a vehicle crashes into an object.
犬が急に道路に突っ込んできて、危うくぶつかりそうになった。
A dog suddenly darted into the road, and I nearly hit it.
眠気に襲われた運転手の車が、電柱に突っ込んだ。
The drowsy driver's car plowed into a utility pole.
彼は返事も待たずに部屋に突っ込んできた。
He barged into the room without waiting for a reply.
3To delve deeply into a topic or matter, examining it or discussing it in depth.
この記事はもう少し突っ込んで書いたほうが読者の関心を引けると思う。
I think this article would draw more reader interest if it went a bit deeper.
専門家にその制度について突っ込んで話を聞いた。
I asked an expert to talk in depth about that system.
4To press someone sharply about inconsistencies or weak points in what they said or did.
記者は大臣の答弁の矛盾を突っ込んだ。
The reporter pressed the minister on the contradictions in his answer.
上司に予算案の甘さを突っ込まれて、返す言葉がなかった。
My boss grilled me on how sloppy the budget proposal was, and I had nothing to say.
弁護士は証人の証言の食い違いを鋭く突っ込んだ。
The lawyer sharply pointed out the inconsistencies in the witness's testimony.
5To meddle in something unrelated or in someone else's affairs; usually in the form 首を突っ込む.
彼はすぐに人の揉め事に首を突っ込みたがる。
He's always quick to poke his nose into other people's disputes.
関係のない話に突っ込まないほうがいい。
You'd better not meddle in matters that don't concern you.
6In manzai comedy, to sharply retort to the "boke" partner's absurd remark; in everyday speech, to make a witty comeback or comment.
相方のボケに彼はすかさず突っ込んだ。
He immediately retorted to his partner's silly joke.
友達の変な冗談に、思わず「それはないでしょ」と突っ込んでしまった。
I couldn't help but quip "no way" at my friend's weird joke.