first strike noun3 •An attack (typically nuclear) launched without warning in the absence of a prior attack by one's opponent, with the intention of destroying one's opponent's ability to retaliate.During the Cold War, both sides feared that the other was preparing to launch a first strike. •A first offense by a lawbreaker, as counted by a three-strikes law.His first strike was when he stole a car to go for a joyride. •One of the first few coins struck from a new set of dies.Collectors pay a premium for first strikes in order to get their hands on coins with the crispest possible detailing. formsfirst strikes