無効(むこう)

Forms

無(む) (without, none) + 効(こう) (effect, validity)

Usage

Used in legal, administrative, and technical contexts for things that have no force or effect. Functions as a noun or na-adjective.

Common collocations

• 無効(むこう)になる: to become invalid
• 無効(むこう)にする: to invalidate, to void
• 無効(むこう)投票(とうひょう): invalid vote, spoiled ballot
• 契約(けいやく)無効(むこう): contract nullification
• 無効(むこう)扱(あつか)い: treated as invalid

Similar words

• 無効(むこう): invalid, void (no legal/practical effect)
• 有効(ゆうこう): valid, effective (the antonym)

Watch out

Do not confuse with the homophone 向(む)こう (over there, the other side).