Debacle
early 19th century (in sense ‘the breaking up of ice in a river’): from French débâcle, from débâcler ‘unleash’, from dé- ‘un-’ + bâcler ‘to bar’ (from Latin baculum ‘staff’).
wiktionary
From French débâcle, from débâcler(“to unbar; unleash”) from prefix dé-(“un-”) + bâcler(“to dash, bind, bar, block”) [perhaps from unattested Middle French and Old French *bâcler, *bacler(“to hold in place, prop a door or window open”)], from Vulgar Latin * bacculare, from Latin baculum(“rod, staff used for support”), from Proto-Indo-European *bak-.
Also attested in Old French desbacler(“to clear a harbour by getting ships unloaded to make room for incoming ships with lading”) and in Occitan baclar(“to close”).
The hypothesis of a derivation from Middle Dutch bakkelen(“to freeze artificially, lock in place”), from bakken(“to stick, stick hard, glue together”) has been discredited by the lack of attestation of bakkelen in Middle Dutch and by it having only the meaning "freeze superficially" in Dutch.
etymonline
debacle (n.)
"disaster," 1848, from French débâcle "downfall, collapse, disaster" (17c.), a figurative use, literally "breaking up (of ice on a river) in consequence of a rise in the water," extended to the violent flood that follows when the river ice melts in spring; from débâcler "to free," earlier desbacler "to unbar," from des- "off" (see dis-) + bacler "to bar," from Vulgar Latin *bacculare, from Latin baculum "stick" (see bacillus).
The literal sense is attested in English from 1802, in geology, to explain the landscapes left by the ice ages. Figurative sense of "disaster" was present in French before English borrowed the word.
