late Old English, "act of giving way and falling down" (a sense now obsolete), from Latin ruina "a collapse, a rushing down, a tumbling down" (source also of Old French ruine "a collapse," Spanish ruina, Italian rovina), which is a derivative of ruere "to rush, fall violently, collapse" (from PIE *reue- (2) "to smash, knock down, tear out, dig up;" see rough (adj.)).
The sense of "descent from a state of prosperity, degradation, downfall or decay of a person or society" is from late 14c. The general meaning "violent or complete destruction" (of anything), "a profound change so as to unfit a thing for use" (of one's principles, one's shirt, etc.) is by 1670s; the sense of "that which causes destruction or downfall" is from early 15c. The meaning "dishonor," of a woman, is from 1620s. Ruins "remains of a decayed building or town" is from mid-15c.; the same sense was in the Latin plural noun.
1580s, "reduce (a place) to ruin," transitive, from ruin (n.) or from French ruiner (14c.). From 1610s as "inflict disaster upon" (someone). The meaning "bring to ruin, damage essentially and irreparably" is by 1650s. The intransitive sense of "fall into ruin" is from c. 1600, now rare or obsolete. The financial sense of "reduce to poverty, wreck the finances of" is attested from 1650s. Related: Ruined; ruining.
"act of bringing to ruin, state of being brought to ruin," 1660s, noun of action or state from the now rare or obsolete verb ruinate "to go to ruin" (1540s), which is from Medieval Latin ruinatus, past participle of ruinare, from Latin ruina (see ruin (n.)).
late 14c., "going to ruin, falling to ruin," from Old French ruinos (Modern French ruineux) and directly from Latin ruinosus "tumbling down, going to ruin," from ruina (see ruin (n.)). Meaning "causing ruin, tending to bring ruin" is from mid-15c.; by 1817 specifically as "excessively expensive." Related: Ruinously; ruinousness.
1560s, "to bring (a building) to ruin, bring into a ruinous condition by misuse or neglect," from Latin dilapidatus, past participle of dilapidare "to squander, waste," originally "to throw stones, scatter like stones," from dis- "asunder" (see dis-) + lapidare "throw stones at," from lapis (genitive lapidis) "stone" (see lapideous). Perhaps the English word is a back-formation from dilapidation. Intransitive sense of "fall into total or partial ruin" is from 1712.
1590s, "an undoing, ruin," from defeat (v.). From c. 1600 as "act of overcoming in a military contest;" by 1690s of other contests and struggles.
mid-14c., "condition of damnation, spiritual ruin, state of the souls of the wicked in Hell," a special theological sense; the general sense of "utter destruction, entire ruin, great harm, death, fact of being lost or destroyed," is by late 14c.; from Old French perdicion "loss, calamity, perdition" of souls (11c.) and directly from Late Latin perditionem (nominative perditio) "ruin, destruction," noun of action from past-participle stem of Latin perdere "do away with, destroy; lose, throw away, squander," from per- "through" (here perhaps with intensive or completive force, "to destruction") + dare "to give" (from PIE root *do- "to give"). The theological sense gradually extinguished the general use of the word.