Taxidermist initially given rotting body part (5)
I believe the answer is:
thigh
'body part' is the definition.
(thigh is a kind of body part)
'taxidermist initially given rotting' is the wordplay.
'initially' indicates taking the first letters.
'given' means one lot of letters go next to another.
'rotting' becomes 'high'.
The initial letter of 'taxidermist' is 't'.
't'+'high'='THIGH'
(Other definitions for thigh that I've seen before include "Part of member" , "Upper part of the leg" , "Upper joint of the leg" , "Leg between knee and hip" , "top of pin" .)