1610s, "to thrust forward or onward, to drive along;" 1640s, "to cause to stick out," from Latin protrudere "thrust forward; push out," from pro- "forward" (see pro-) + trudere "to thrust" (see extrusion). Intransitive meaning "jut out, bulge forth" recorded from 1620s. Related: Protruded; protruding.[protrude etymology, protrude origin, 英语词源]