Sarcasm, informally (5)
I believe the answer is:
snark
'sarcasm informally' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for snark that I've seen before include "One famously hunted" , "creature fitly hunted" , "Animal hunted in verse" , "Carroll's mythical animal" , "Creature charmed with smiles and soap" .)