walk-in(a)
n. person who walks in without having an appointment"the emergency room was overrun with walk-ins"
an operative who initiates his own defection (usually to a hostile country) for political asylum an assured victory (especially in an election) 同义词：waltz
a small room large enough to admit entrance v.enter by walking 同义词：walk in
adj.(of e.g. closets or refrigerators) extending very far enough back to allow a person to enter"a deep walk-in refrigerator"; " walk-in closets"