Left help to be put down (4)
I believe the answer is:
laid
'be put down' is the definition.
(to lay something is to put it down somewhere)
'left help' is the wordplay.
'left' becomes 'l' (common abbreviation).
'help' becomes 'aid' (synonyms).
'l'+'aid'='LAID'
'to' is the link.
(Other definitions for laid that I've seen before include "Produced (an egg)" , "Deposited" , "Put down like dial" , "Prepared (a trap)" , "settled" .)