Impossible to feel limber with piece rewritten about gym (13)
I believe the answer is:
imperceptible
'impossible to feel' is the definition.
(I've seen this before)
'limber with piece rewritten about gym' is the wordplay.
I cannot quite understand how this works, but
'piece' could be 'r' (abbreviation for Rook) and 'r' is located in the answer.
'about' could be 'c' (abbreviation for 'circa') and 'c' is located in the answer.
'gym' could be 'pt' and 'pt' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for imperceptible that I've seen before include "Not discernible by the senses" , "Too slight to be noticed" , "Too small to be noticed" , "Unnoticeable" , "Impossible to feel" .)