IPA: /ˈliːsər/
KK: /ˈliːsər/
A person or entity that leases property or equipment to another party.
The leaser signed the contract to rent the apartment for a year.
Leaser → It is formed from "lease" (from Old French *laisser*, meaning to let or allow) and "-er" (meaning a person who). A leaser is a person who allows or lets something to be used by another.
Think of someone who 'lets' ('lease') something to another person — that's what a leaser does.