### Question
How is the term annuity defined?


### Answer
The term **annuity** is defined in *45 U.S.C. § 231* as the following:

> a monthly sum which is payable on the first day of each calendar month for the accrual during the preceding calendar month

#### Citation:
  - *45 U.S.C. § 231*
  - Heading: **CHAPTER 9-RETIREMENT OF RAILROAD EMPLOYEES > SUBCHAPTER IV-RAILROAD RETIREMENT ACT OF 1974**

