noun
land mine
Literal military explosive device buried underground.
その地域にはまだ地雷が埋まっている。
Land mines are still buried in that area.
noun
sensitive topic; trigger; taboo subject
Colloquial metaphorical use: a topic that, if brought up, will cause a strong negative reaction or argument.
Bringing up marriage with him is a minefield.
noun
hidden trap; pitfall; booby trap
Colloquial: something that looks good initially but turns out to be a disaster, like a bad product or deal.
このゲーム、最初は面白いけど後半が地雷だった。
This game was fun at first, but the second half was a total letdown.