A pair of animals, or an insect, for instance? (7)
I believe the answer is:
anagram
'instance?' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'a pair of animals or an insect' is the wordplay.
I cannot really see how this works, but
'a' could be 'an' and 'an' is present in the answer.
'an' could be 'a' and 'a' is found within the answer.
The remaining letters 'gram' is a valid word which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
'for' acts as a link.
(Other definitions for anagram that I've seen before include "Word(s) rearranged to form others" , "characters on the move" , "Type of word puzzle" , "Word rearranging another's letters" , "Cruciverbal jumble" .)