re ‧ tal ‧ i ‧ a ‧ tion /rɪˌtæliˈeɪʃ ə n/ BrE AmE noun [uncountable]
action against someone who has done something bad to you ⇨ revenge
in retaliation (for something)
This action was undoubtedly in retaliation for last week’s bomb attack.
retaliation against
the threat of massive retaliation against British troops