un·fas·tenBrE/ʌnˈfɑːsn/NAmE/ʌnˈfæsn/verbpresent simple - I / you / we / theyunfastenBrE/ʌnˈfɑːsn/NAmE/ʌnˈfæsn/present simple - he / she / itunfastensBrE/ʌnˈfɑːsnz/NAmE/ʌnˈfæsnz/past simpleunfastenedBrE/ʌnˈfɑːsnd/NAmE/ʌnˈfæsnd/past participleunfastenedBrE/ʌnˈfɑːsnd/NAmE/ʌnˈfæsnd/ -ing formunfasteningBrE/ʌnˈfɑːsnɪŋ/NAmE/ʌnˈfæsnɪŋ/~sthtoundosththatisfastened解开;松开;打开◆tounfastenabelt/button, etc.解开皮带、纽扣等OPPfasten