bo‧nus S2 [countable]
money added to someone's wages, especially as a reward for good work:
Long-term savers qualify for a cash bonus.
Further additions to your pay may take the form of bonus payments.
a Christmas bonus
Each worker receives an annual bonus.
a £20,000 bonus
something good that you did not expect in a situation
Britain's possession of North Sea oil has proved a bonus for British technology.
He promised to take me to the match with the added bonus of an afternoon off school.
3 British EnglishBFITTC
a reduction in the cost of your car insurance when you do not make a claim in a particular year