Amphibian originally eaten for tea (3)
I believe the answer is:
eft
'amphibian' is the definition.
(eft is a kind of amphibian)
'originally eaten for tea' is the wordplay.
'originally' indicates taking the first letters.
The initial letters of 'eaten for tea' is 'EFT'.
(Other definitions for eft that I've seen before include "Swimmer with feeble legs" , "Pond creature" , "Newt (archaic)" , "Kind of newt found in clefts" , "Juvenile twenty-three Ac; rhymes with sinister" .)