What does the idiom struck up means?

The idiom "struck up" can have a few different meanings depending on the context. Here are the most common:

1. To begin a conversation or relationship:

* Example: "We struck up a conversation about the weather while waiting in line."

2. To start playing a piece of music:

* Example: "The band struck up a lively tune for the dancing."

3. To start something suddenly, usually in a positive way:

* Example: "She struck up a friendship with her neighbor."

4. To raise something, like a flag or a sail:

* Example: "The pirates struck up their Jolly Roger."

The specific meaning of "struck up" will be determined by the context of the sentence.