Webster’s Revised Unabridged Dictionary · 1913
Mono-
Mon′o- (mŏn′ō·), Mon- (mŏn·) . [Gr. μόνος.] A prefix signifying one, single, alone; as, monocarp, monopoly; (Chem.) indicating that a compound contains one atom, radical, or group of that to the name of which it is united; as, monoxide, monosulphide, monatomic, etc.