Touching a pet, itch terribly (8)
I believe the answer is:
pathetic
'touching' is the definition.
(I've seen this before)
'a pet itch terribly' is the wordplay.
'terribly' indicates anagramming the letters.
'a'+'pet'+'itch'='apetitch'
'apetitch' with letters rearranged gives 'PATHETIC'.
(Other definitions for pathetic that I've seen before include "Feeble; inspiring pity" , "Distressing" , "Sort of fallacy" , "Derisory" , "Miserably inadequate - way to tip cheat" .)