Head of urology given endlessly stretchy tool (7)
I believe the answer is:
utensil
'tool' is the definition.
(I've seen this before)
'head of urology given endlessly stretchy' is the wordplay.
'head of' indicates taking the first letters.
'given' means one lot of letters go next to another.
'endlessly' means to remove the last letter.
'stretchy' becomes 'tensile' (I've seen this in another clue).
The initial letter of 'urology' is 'u'.
'tensile' with its final letter taken away is 'tensil'.
'u'+'tensil'='UTENSIL'
(Other definitions for utensil that I've seen before include "Gadget" , "Let us in (anag) -- implement" , "knife, maybe" , "A kitchen pot or pan" , "Containers for kitchen use" .)