1.
interest (financial)
Money paid for the use of borrowed money, or earned on deposited money.
利息 refers to the money earned on savings or paid on loans — the actual amount of interest, not the percentage rate.
COMMON PATTERNS:
- 利息がつく: to earn/accrue interest
- 利息を払う: to pay interest
- 利息を受け取る: to receive interest
- 利息が高い/低い: interest is high/low
SIMILAR WORDS:
- 利子: interest (virtually synonymous; 利子 is slightly more formal and common in written/legal contexts)
- 金利: interest rate (the percentage, not the money amount)
- 利率: interest rate (more technical/formal than 金利)
USAGE NOTE:
利息 applies to both interest earned on deposits and interest charged on loans. Context makes clear which is meant. In Japan's long era of low interest rates, 利息がほとんどつかない (earning almost no interest) has been a common complaint about bank savings.