- (transitive, idiomatic) To start something with somebody else, such as a conversation or relationship.
- To make him feel welcome, she struck up a conversation with the newly arrived guest.
- He struck up a friendship with Redford that was to last for many years.
- (intransitive, idiomatic) To start something, usually playing live music.
- The band struck up and everyone started to dance.
- (ergative)The bride entered the church just as the "Wedding March" struck up.
- To raise (as sheet metal), in making dishes, pans, etc., by blows or pressure in a die.