Physics.
1. the average time that an unstable particle or nucleus survives before it decays.
2. See decay time . Also called average life, lifetime .
Physics.
1. the average time that an unstable particle or nucleus survives before it decays.
2. See decay time . Also called average life, lifetime .
Random House Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012