monocyclic Syllabification: (mon·o·cy·clic)Pronunciation: /ˌmänōˈsīklik, -ˈsik-/Definition of monocyclic adjective 1 Chemistry having one ring of atoms in its molecule. 2of or relating to a single cycle of activity. monocyclic in other Oxford dictionaries Definition of monocyclic in the British & World English dictionary