a bomb that has a detonating mechanism that can be set to go off at a particular time
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 basin for washing the hands (`wash-hand basin' is a British expression)
a bathroom sink that is permanently installed and connected to a water supply and drainpipe; where you can wash your hands and face; "he ran some water in the basin and splashed it on his face"