I.down1[美 daʊn, 英 daʊn]副down often appears as the second element of certain verb structures in English (back down, clamp down, tone down, etc). For translations, see the relevant verb entry (back, clamp, tone, etc).
Another was the trickle down effect, which posited that, as an economy developed, its lower social strata would benefit from the achievements of free enterprise.
To avoid a surprising failure at the end of high school, standards trickle down through all the lower grades, with regular assessments through a variety of means.
This tends to support an emigration flow since even improving conditions in the emigrant's country take a while to trickle down to potential emigrants to convince them not to leave.