time bomb is a noun meaning "a problematic situation that will eventually become dangerous if not addressed". It carries 2 recorded senses.
a problematic situation that will eventually become dangerous if not addressed
“India is a demographic time bomb”
“the refugee camp is a ticking bomb waiting to go off”
a bomb that has a detonating mechanism that can be set to go off at a particular time
Definitions, synonyms and semantic relations for time bomb come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.