Look to for support (6,2)
'look to for support' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lean on that I've seen before include "bully" , "Seek support from" , "Informally, seek to influence by intimidation" , "Cling to" , "Put trust in" .)
(Another definition for depend on that I've seen is " Put trust in".)