To explain the fundamentals of something to someone.

Alternative form of show one's true stripes

Alternative form of wave the white flag

To show cowardice.

(idiomatic) One must finish what one has started; things must continue no matter what.

(intransitive, idiomatic) To demonstrate oneself to be dominant; to show that one has the upper hand.

Alternative form of show who's boss

(law) A type of court order that requires a person to justify, explain, or prove something to the court.

plural of order to show cause

Third-person singular simple present indicative form of show who's boss