One who casually drops in (visits unannounced or without appointment). / An informal event that does not require booking in advance. / A place that can be visited casually, without an appointment.

plural of drop

Third-person singular simple present indicative form of drop

(colloquial) To visit informally and spontaneously.

(intransitive) Of a liquid: to fall in drops or droplets. / (intransitive, also figuratively) To fall (straight down) under the influence of gravity, like a drop of liquid.

(pharmacology) A dose of liquid medicine in the form of a drop (sense 1). / (pharmacology, chiefly in the plural) A liquid medicine that is intended to be administered in drops (sense 1).

simple past tense and past participle of drop

(idiomatic) To arrive casually and unannounced, with little or no warning; also, to visit without an appointment. / (surfing) To paddle into and take off on a wave another surfer is already riding.

Alternative spelling of drop-in.

allowed to drop or fall. / (of a phone call) suddenly disconnected.