Refers to a person who borrows something, owes money, or rents property. The specific meaning depends on context.
The borrower must sign the contract.
その借り受け人は毎月家賃を支払っている。
That tenant pays rent every month.
債務者 specifically means 'debtor' in a financial or legal sense, whereas 借り受け人 can also refer to a tenant or general borrower.
Compound of 借り受け (borrowing, receiving on loan) and 人 (person).