Monosyllable (noun)

A word or word element consisting of a single syllable.

Origin:

From the greek monos, meaning "single" and syllabē, meaning "syllable".

Examples:

1. The word "dog" is a monosyllable.
2. He spoke in monosyllables.
3. The monosyllables are often used as interjections.
4. The poem is composed of monosyllables.
5. The monosyllables are easier to rhyme.