A pound for white top (3)
I believe the answer is:
alb
'white top' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'a pound' is the wordplay.
'pound' becomes 'lb' (abbreviation for the unit of weight).
'a'+'lb'='ALB'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for alb that I've seen before include "Long white church vestment" , "Priests robe made in Balbriggan" , "Devotional vestment" , "Clerical vestment." , "the vicar might put on?" .)