late 14c., in medicine, "act of bursting or breaking," in reference to a vessel, etc. of the body, from Old French rupture and directly from Latin ruptura "the breaking (of a vein), fracture (of an arm or leg)," from past-participle stem of rumpere "to break" (from PIE root *runp- "to break;" see corrupt (adj.)).
Specifically as "abdominal hernia" from early 15c. The sense of "breach of friendly relations or concord" is by 1580s; the general sense of "act or fact of breaking or bursting" is by 1640s. Rupturewort (1590s) was held to be efficacious in treating hernias, etc.
1739, in medicine, "to break, burst" (a vessel, etc.), from rupture (n.). The intransitive sense of "suffer a break" is by 1863. Related: Ruptured; rupturing. The old verb was rupt (Middle English rupten, in medicine, early 15c.), from Latin ruptus. Ruptured duck (1945) was U.S. GI's dismissive term (based on its design) for the discharge button they were awarded. Earlier it was used in a sense of "a damaged aircraft" (1930). Compare lame duck.