What does "put a lean on/against" mean?
Lean on, Informal:
To exert influence or pressure on in order to gain cooperation, maintain discipline, or the like: The state is leaning on the company to clean up its industrial wastes.
On the other hand, if you change your spelling to use the legal term, "lien" such as property or real estate lien, you get a different meaning:
A right given to another by the owner of property to secure a debt, or one created by law in favor of certain creditors.
I hope this helps.