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.
Maybe there's a link between them I don't understand?
'iron by crossing lake' is the wordplay.
'iron' becomes 'Fe' (chemical symbol for iron).
'by' becomes 'x' (as in 'multiplied by').
'crossing' means one lot of letters goes inside another (to cross can mean to go over or around).
'lake' becomes 'L' (geographical abbreviation).
'fe'+'x'='fex'
'fex' enclosing '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)" .)