Balcony arrived from Italian in the 1610s, from balcone, and the -ony ending is an Italian augmentative -one, "a big one," bolted onto balco, "scaffold." So a balcony is, literally, a big beam. It belongs with piano, opera, ghetto and umbrella in the wave of Italian architectural, musical and artistic vocabulary that English absorbed in the 1600s and 1700s.
Two details are worth noticing. First, the Italian word is not Italian all the way down: balco is Germanic, probably from Langobardic, the language of the Germanic people who ruled northern Italy — the same root that gives English balk. So the word is a Germanic beam that went to Italy, grew a suffix, and came back. Second, until about 1825 English stressed it on the second syllable, bal-CO-ny, which sounds absurd now and shows how recently the modern pronunciation settled.
balcony (n.) 1610s, "platform projecting from a wall of a building surrounded by a wall or railing," from Italian balcone , from balco "scaffold," which is from a Germanic source (perhaps Langobardic *balko- "beam"), from Proto-Germanic *balkon- (see balk (n.)). With Italian augmentative suffix -one . From 1718 as "gallery in a theater." Until c. 1825, regularly accented on the second syllable. Related: Balconied . also from 1610s
balcony came in through Later and wider borrowings, and its spelling follows that family's conventions.
What gives it away on the page
| -o/-a/-i endings, gh for hard g, cc | Italian — music, food, and architecture.piano, opera, graffiti, spaghetti, ghetto, broccoli, balcony |
Later and wider borrowings in the spelling guide · guess another word's family