Move supply of iron by crossing lake (4)
I believe the answer is:
flex
'move supply' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'iron by crossing lake' is the wordplay.
'iron' becomes 'Fe' (chemical symbol for iron).
'by' becomes 'x' (2 by 4 is 2 x 4).
'crossing' indicates putting letters inside (to cross can mean to go over or around).
'lake' becomes 'L' (geographical abbreviation).
'fe'+'x'='fex'
'fex' going around 'l' is 'FLEX'.
'of' is the link.
Can you help me to learn more?
(Other definitions for flex that I've seen before include "Bend (muscle?)" , "Insulated wire cable" , "Supply contract" , "Bend (muscles)" , "Contract (a muscle)" .)