Nail unfinished work (4)
I believe the answer is:
stud
This might be a double definition.
'nail' is the first definition.
(I've seen this before)
'unfinished work' is the second definition.
The definition and answer can be both acts as well as being singular nouns.
Maybe there's an association between them I don't understand?
Can you help me to learn more?
(Other definitions for stud that I've seen before include "Specified arrangement" , "Gripper under a boot" , "Type of poker, a collar and a farm" , "Knob; fastener; boss" , "Male horse kept for breeding" .)