mono-

1. a combining form meaning “alone,” “single,” “one” (monogamy); specialized in some scientific terms to denote a monomolecular thickness (monolayer) and adapted in chemistry to apply to compounds containing one atom of a particular element (monohydrate).

combining form

1. one; singlemonochrome; monorail
2. indicating that a chemical compound contains a single specified atom or groupmonoxide

word-forming element meaning “one, alone; containing one (atom, etc.),” from Greek mono-, comb. form of monos “single, alone,” from PIE root *men- “small, isolated” (cf. Greek manos “rare, sparse,” Armenian manr “thin, slender, small,” and perhaps English minnow). pref.

1. One; single; alone:monomorphic.
2. Monomolecular; monatomic:monolayer.
3. Containing one atom, molecule, or group:monomer.

1. A prefix that means “one, only, single,” as in monochromatic, having only one color. It is often found in chemical names where it means “containing just one” of the specified atom or group, as in carbon monoxide, which is carbon attached to a single oxygen atom.