- having one cycle.
- Botany. arranged in a single whorl, as the parts of certain flowers.
- Chemistry. of or relating to a molecular structure containing one ring.
- Also: mononuclear (of a chemical compound) containing only one ring of atoms
- (of sepals, petals, or stamens) arranged in a single whorl
- (of a plant) having a life cycle that is completed in one year
- Having a single cycle, as of activity or development.
- Having a single whorl, as certain flowers and the shells of certain invertebrates.
- Having a molecular structure with only one ring. Benzene and toluene are monocyclic molecules.