Word: 失效 (shīxiào) 失效 dictionary entry shīxiào to fail; to lose effectiveness Full dictionary entry for 失效 Example sentences using 失效 2 sentences, showing page 1 of 1. 优惠券已经过期，早就失效了。 Yōuhuìquàn yǐjīng guòqī, zǎojiù shīxiàole. The coupon has expired and is long since no longer valid. 这张优惠券昨天就失效了。 Zhè zhāng yōuhuìquàn zuótiān jiù shīxiàole. This coupon expired yesterday.