| 释义 |
half-lifeBrE /ˈhɑːf laɪf/NAmE /ˈhæf laɪf/ noun [C] (physics 物理) the time taken for the radioactivity of a substance to fall to half its original value （放射性物质的）半衰期the time taken for the concentration of a substance in the body to fall to half its original value （体内物质的）半衰期 |