Part of the set for the first play (4)
I believe the answer is:
prop
'part of the set' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'for the first play' is the wordplay.
'for' becomes 'pro' (as in being 'pro' or in favour of something).
'the first play' becomes 'p' (1st letter of 'play').
'pro'+'p'='PROP'
Can you help me to learn more?
(Other definitions for prop that I've seen before include "Moveable object used on stage" , "one playing Rugby" , "Object used on the set of a play" , "Back up" , "Hold (up), support" .)