What word or phrase does your mother always say?
1620s, from French déférent (16c.), from Latin deferentem (nominative deferens), present participle of deferre "to carry down or away" (see defer (v.2)). Earlier in Middle English as a word in astronomy (early 15c.).
deferent def·er·ent (děf'ər-ənt, děf'rənt)
Carrying down or away, as a duct or vessel.