Contemptible individual returning a Scrabble piece (7)

I believe the answer is:
reptile
'contemptible individual' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'returning a scrabble piece' is the wordplay.
'returning' says the letters should be written backwards.
'a' becomes 'per' (eg 'one a day' means 'one per day').
'scrabble piece' becomes 'tile' (Scrabble is played with tiles with letters on).
'per' in reverse letter order is 'rep'.
'rep'+'tile'='REPTILE'
Can you help me to learn more?
(Other definitions for reptile that I've seen before include "Turtle or snake say" , "Cold-blooded beast" , "Snake or crocodile, say" , "Cold-blooded creature" , "Somebody grovelling" .)
