Farm animals Tom possibly let out (6)
I believe the answer is:
cattle
'farm animals' is the definition.
(I've seen this before)
'tom possibly let out' is the wordplay.
'tom possibly' becomes 'cat' (a tom is a male cat).
'out' indicates an anagram (out can mean wrong or inaccurate).
'let' is an anagram of 'tle'.
'cat'+'tle'='CATTLE'
(Other definitions for cattle that I've seen before include "Stock farm" , "Cows, steers" , "Jersey and Guernsey?" , "Domestic bovines" , "Farm animals" .)