a small house, especially one connected to a large apartment building.
an apartment, usually of two floors connected by an internal staircase; duplex apartment.
Origin of maisonette
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
self-contained living accommodation often occupying two floors of a larger house and having its own outside entrance
Word Origin for maisonette
C19: from French, diminutive of maison house
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
1818, "small house," from French maisonnette, diminutive of maison "house" (11c.), from Latin mansionem (see mansion). Meaning "a part of a building let separately" is from 1912.
Online Etymology Dictionary, © 2010 Douglas Harper