Contains

• daring

  A challenge to do something dangerous or foolhardy; "he could never refuse a dare".

• confrontation

  A bold challenge.

• call-out

  A challenge to a fight or duel.

• defiance

  A hostile challenge.

• calling into question

  A challenge to defend what someone has said.

• demand for identification

  As by a sentry.

• gauntlet

  To offer or accept a challenge; "threw down the gauntlet"; "took up the gauntlet".