Affixes

Examples include monocle (Latin oculus, eye), a single eyeglass; monologue, a long speech by a single actor; monophonic, of sound reproduction that uses only one channel, as compared with stereophonic; monopoly (Greek pōlein, sell), the exclusive possession or control of the supply or trade in a commodity or service; monorail, a railway in which the track consists of a single rail; monotone, a sound, especially of someone's voice, that varies in pitch only slightly (the quality of sameness this implies has led to a common sense of monotonous and monotony for a lack of variety or a tedious routine).

In chemistry, mono‑ refers specifically to a substance that contains only a single instance of an atom or group, as in monoxide, an oxide containing one atom of oxygen in its molecule; monoamine, a compound having a single amine group in its molecule; monomer, a molecule that can be bonded to other identical molecules to form a polymer.