from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A unit in a low-rise apartment complex that includes a substantial amount of open, usually landscaped ground.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A detached mother-in-law apartment or cottage on the same parcel as the main house.
- n. One of a set of low-rise apartment buildings built among landscaped grounds and often arranged around courtyards that are open at one end.
So called since this form of housing is usually a cottage built in a home's back yard garden area. (Wiktionary)