valid/ˋvælId; ˈvæləd or ˈvælId/adj 1 a valid ticket, document, or agreement is legally or officially acceptable [ invalid ] 有效的: a valid passport 有效的护照Your return ticket is valid for three months. 你的往返票有效期为三个月。2 a valid reason, argument etc is based on something reasonable or sensible 正当的﹐合理的: a valid criticism 正当的批评 —validity /vəˋlIdətI; vəˈlIdəti or vəˈlIdIti/n [U]