Mortgagor, e.g.

• Holder of encumbered property
• One with a claim against him
• Holder of claimed property
• One whose property is claimed legally
• One with a mortgage, e.g.
• Person with a mortgage, e.g
• Holder of a collateral loan
• One with a collateral loan
• One whose property is subject to a legal claim

Wiktionary Word definitions in Wiktionary
n. (context legal English) One who has right of possession of goods but not right of property; the registered owner.