trickle

Concise Oxford English Dictionary © 2008 Oxford University Press:
trickle/ˈtrɪkl/

▶verb

• 1 (of a liquid) flow in a small stream.

• 2 come or go slowly or gradually: the congregation began to trickle in.

• 3 (trickle down) (of wealth) gradually benefit the poorest as a result of the increasing wealth of the richest.

▶noun

• 1 a small flow of liquid.

• 2 a small number of people or things moving slowly.

– origin ME: imitative.