チャレンジ

(1)oppose, as in hostility or a competition; "You must confront your opponent"; "Jackson faced Smith in the boxing ring"; "The two enemies finally confronted each other"

(2)戦争行為または競争などにおいて敵対する

(3)issue a challenge to; "Fischer challenged Spassky to a match"

(4)挑戦を表明する

(1)