A landmine is a bomb hidden in the ground. It is meant to wait. When a person steps on it, or a vehicle rolls over it, it explodes. Armies bury them to stop soldiers and trucks; some are made to kill people, others to wreck tanks. The cruel part, and the part news stories keep returning to, is that the mine does not know when the war ended: farmers, children, and animals still meet old ones years later. The word is grim and concrete. English more often uses minefield — a whole patch of ground planted with mines — when it wants a metaphor for a situation full of hidden trouble. Landmine itself usually stays literal, though you will hear it stretched. Mine here is the explosive, not ‘that thing is mine,’ and not first of all a coal mine — though actually the bomb sense grew out of soldiers digging under walls (mining) and setting charges. Later they skipped the tunnel and just buried the charge. That is the landmine.