unannounced

adj without prior warning or notification; unexpected 未事先宣布的; 未通知的; 突如其来的: make unannounced safety checks on equipment 对设备进行突然的安全检查 * He arrived unannounced. 他未事先通知而来到.

unaccommodating, unaccompanied, unaccountable, unaccountably, unaccounted, unaccustomed, unacknowledged, unadopted, unadulterated, unaffected, unaffordable, unafraid, unaided, unalloyed, unalterable, unaltered, unambiguous, unanimity, unanimous, unanimously, unanswerable, unanswered, unanticipated, unappreciated, unapproachable, unarmed, unarticulated, unashamed, unashamedly, unasked, unasked for, unassailable, unassuming, unassumingly, unattached, unattended, unattractive, unavailable, unavailing, unavoidable,