The term 'let by' is a legal phrase that is used to describe a situation in which a landlord allows a tenant to remain in a property after the end of a lease agreement. This is usually done on a temporary basis, and the tenant is expected to vacate the property when the landlord requests it. The term 'let by' is also used to refer to a situation in which a tenant is allowed to sublet a property from another tenant. In this case, the tenant is responsible for paying rent to the original tenant, rather than the landlord.