1to slip into; to crawl into (under); to hide oneself by getting into a narrow or low place
猫が家具の下に潜り込んで出てこない。
The cat slipped under the furniture and won't come out.
子どもが布団に潜り込んで眠ってしまった。
The child crawled under the futon and fell asleep.
強風で車の下に何かが潜り込んだようだ。
It seems something got tucked under the car because of the strong wind.
2to sneak into; to infiltrate (enter secretly or covertly)
彼はパーティーに招待されていなかったが、こっそり会場に潜り込んだ。
He wasn't invited to the party, but he sneaked into the venue.
行列に紛れて会場に潜り込むのは危険だ。
It's dangerous to blend into the crowd and sneak into the venue.
不審者が敷地内に潜り込んでいると連絡があった。
We received a report that a suspicious person had sneaked onto the premises.