〔有効性を失う〕lapse;〔法律用語〕lose validity;〔期限が切れる〕expire, 《口》 run out
- その契約はとっくに失効していた
- The contract had lapsed many years before.
- 更新しなかったので免許証は失効となった
- My license expired [ran out] because I didn't renew it./The license lost its validity because it had not been renewed.
- このカードは失効している
- This card 「has expired [is invalid].