1 verb (intransitive always + adv/prep)
1 if liquid trickles somewhere, it flows slowly in drops or in a thin stream
(+ down/into/out): The tears trickled down her cheeks.
2 if people, vehicles, goods etc trickle somewhere, they move there slowly in small groups or amounts
(+ in/into/away): The first few fans started to trickle into the stadium. 2 noun (singular)
1 a thin slow flow of liquid: The water in the stream had been reduced to a trickle.
2 a movement of people, vehicles, goods etc into a place in very small numbers or amounts: Recent legislation has reduced immigration to a trickle.

Longman dictionary of contemporary English. 2004.