1620s, "bearing off or away," 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 Ptolemaic astronomy (early 15c.) to explain the apparent motion of planets.
defenseless
defensible
defensive
defer
deference
deferent
deferential
deferment
deferral
deferred
defiance