Had Adam a spare one? (3)
I believe the answer is:
rib
'spare one?' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for rib that I've seen before include "Eve was known as Adam's ..." , "spare one?" , "Curved bone joined to the spine" , "Slender bone" , "that was sacrificed for wife originally" .)