noun
Refers to a person who borrows money or goods. Often used in financial or legal contexts.
銀行は借り主の信用を調べる。
The bank checks the borrower's credit.
Refers to a person who rents or leases property, such as an apartment or land.
借り主は毎月家賃を払う義務がある。
The tenant is obligated to pay rent every month.
貸し主 means 'lender' or 'landlord', the opposite party in a borrowing or rental relationship.
Compound of 借り (kari, 'borrowing') + 主 (nushi, 'owner' or 'person'). The reading かりぬし is a straightforward combination.