one-shot
adjective
USuk/ˌwʌnˈʃɒt/us/ˌwʌnˈʃɑːt/(UKone-off)happeningonlyonce:
一次性的They gave him a one-shotpaymenttocompensatefor theextrahoursthat he had towork.他们一次性支付给他一笔钱作为他必须加班的补偿。
Rarely & infrequently
- (every) now and then/againidiom
 - blue moon
 - ever and anon
 - every
 - few
 - fit
 - in/by fits and startsidiom
 - occasion
 - occasional
 - occasionally
 - odd
 - odd jobs
 - once
 - one
 - one-time
 - rarely
 - seldom
 - ship
 - sometimes
 - time