Say the others lose small bird (5)
I believe the answer is:
egret
'bird' is the definition.
(egret is a kind of bird)
'say the others lose small' is the wordplay.
'say' becomes 'eg' (both can mean 'for example').
'the others' becomes 'rest' (eg the rest of a group).
'lose' suggests deleting specific letters.
'small' becomes 's' (abbreviation - e.g. clothes size).
'rest' with 's' taken away is 'ret'.
'eg'+'ret'='EGRET'
(Other definitions for egret that I've seen before include "Type of heron" , "Mainly white heron" , "Bird eating fish" , "(Usually) white heron" , "Heron-like wader" .)