drop by
无预约地访问或参观某人
口语·日常社交，表示非正式拜访
英文释义
to visit someone briefly and without making an appointment
例句
Feel free to drop by my office anytime if you have questions.
典故来源
源自“顺便拜访”的简洁表达，drop表示短暂停留，by表示经过，合起来指非正式顺路访问。