This one was a question my son asked the other day. Why do we use the same word for the two different meanings of stable–the adjective and then the noun? Are they from the same root?
(Why yes, my children do ask questions like this regularly, LOL.)
The short answer is yes, they’re from the same Latin word. The longer answer is that both adjective and noun came to English through Old French, the adjective–meaning, at the time, “trustworthy, reliable”–predating the noun by a few decades, though both were in the English language from the 12th or 13th centuries. The meanings really haven’t changed that much over the years, either. The noun has always been a building or stall where domestic animals are kept. The adjective shifted ever so slightly from “trustworthy” to “steadfast, constant, secure.” (And was applied to isotopes in 1902!)
The Latin root from which both meanings come is sta– (with different suffixes applied for noun and adjective), meaning, not surprisingly, “to stand.” Hence why it applies both to a building and to an upstanding character.
So there we have it, O son of mine. 😉