c. 1400, expulsioun, in medicine, "act of expelling matter from the body," from Old French expulsion or directly from Latin expulsionem (nominative expulsio), noun of action from past-participle stem of expellere "drive out" (see expel). From late 15c. as "forcible ejection, compulsory dismissal, banishment" as from a school or club.
late 14c., "action of going out, an issuing forth;" mid-15c., "act of putting or driving out, expulsion, ejection;" verbal noun from out (v.). Original senses are now obsolete. The meaning "an excursion, a pleasure-trip" is from 1821.
1610s, "expulsion, action of driving away" (a sense now obsolete), noun of action from propuls-, past-participle stem of Latin propellere "to propel" (see propel). The meaning "act of driving forward; propulsive force" is attested by 1799.
late 14c., desolacioun, "sorrow, grief, personal affliction;" c. 1400, "action of laying waste, destruction or expulsion of inhabitants;" from Old French desolacion (12c.) "desolation, devastation, hopelessness, despair" and directly from Church Latin desolationem (nominative desolatio), noun of action from past-participle stem of desolare "leave alone, desert," from de- "completely" (see de-) + solare "make lonely," from solus "alone" (see sole (adj.)).
Meaning "condition of being ruined or wasted, destruction" is from early 15c. Sense of "a desolated place, a devastated or lifeless region" is from 1610s.
"hind-quarters, back-end, or buttocks of an animal," the part to which the tail is attached, mid-15c., from a Scandinavian source (compare Danish, Norwegian rumpe, Swedish rumpa), from or corresponding to Middle Dutch romp, German Rumpf "trunk, torso."
Specifically of this part used as food by late 15c. The figurative sense of "small remnant, tail-end of anything" derives from the notion of "tail" and is recorded from 1640s in reference to the English Rump Parliament (December 1648-April 1653), so called from sitting after the expulsion of the majority of members of the Long Parliament in Pride's Purge. As an adjective from c. 1600. Also in 18c. and 19c. a verb, "to turn one's back to" as a snub.