dɪˈkeɪ v. & n. --v. 1 a intr.
rot,
decompose. b tr.
cause to rot or decompose. 2 intr. & tr.
decline or cause to decline in
quality,
power,
wealth,
energy,
beauty, etc. 3 intr.
Physics a (usu. foll. by to) (of a
substance etc.)
undergo change by
radioactivity. b undergo a
gradual decrease in
magnitude of a
physical quantity. --n. 1 a
rotten or
ruinous state; a process of wasting
away. 2 decline in
health, quality, etc. 3 Physics a change
into another substance etc. by radioactivity. b a decrease in
the magnitude of a physical quantity,
esp. the
intensity of
radiation or
amplitude of oscillation. 4 decayed
tissue. øødecayable adj. [ME f. OF decair f. Rmc (as
DE-, L cadere fall)]