gratuity
/grəˈtjuːətɪ/noun
(pl. -ies)
1- money given in return for some service or favour, in particular赏钱, 酬谢金, 尤指：
formal a tip given to a waiter, taxi driver, etc
〈正式〉小费。
1.1
- Brit. a sum of money paid to an employee at the end of a period of employment〈英〉（在结束雇佣关系时雇主付给雇员的）遣散费; 退职金。
词源
late 15th cent. (denoting graciousness or favour)： from Old French gratuité or medieval Latin gratuitas 'gift'， from Latin gratus 'pleasing， thankful'.