annuity
n.
early 15c., "a yearly allowance, grant payable in annual installments," from Anglo-French and Old French annuité (14c.) or directly from Medieval Latin annuitatem (nominative annuitas), from Latin annus "year" (see annual, adj.). Meaning "an investment that entitles one to equal annual payments" is from 1690s.
〔蒋〕[ann 年，-u 连接字母，-ity名词后缀] 年金；年金享受权
〔李〕[annu=year 年；-ity n.=thing connected with 表相关事物→“money connected with one year 按一年计算的钱”→] n. yearly allowance or income年金；年收入