Definitions of dare:

• noun:   a challenge to do something dangerous or foolhardy

  Example: "He could never refuse a dare"

• verb:   to be courageous enough to try or do something

  Example: "I don't dare call him, she dares to dress differently from the others"

• verb:   take upon oneself; act presumptuously, without permission

  Example: "How dare you call my lawyer?"

• verb:   challenge

  Example: "I dare you!"

• name:  A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #12655)