Fingerprint a doctor β both hands (5)
I believe the answer is:
whorl
'fingerprint' is the definition.
(I've seen this before)
'a doctor both hands' is the wordplay.
'a doctor' becomes 'who' (I have seen 'Fictional doctor' mean 'who' so perhaps 'doctor' could also mean 'who').
'both hands' becomes 'rl'.
'who'+'rl'='WHORL'
(Other definitions for whorl that I've seen before include "ring of leaves" , "Fingerprint circle" , "Loopy shape" , "botanical feature" , "Fingerprint's circular ridge" .)