1. Adjective
Consisting of four; by fours, or in sets of four.
2. Adjective
Later than, or subsequent to, the Tertiary; Post-tertiary; as, the Quaternary age, or Age of man.
3. Noun
The number four.
4. Noun
The Quaternary age, era, or formation. See the Chart of Geology.
5. Noun
the cardinal number that is the sum of three and one
Vocabulary classified under Mathematics
More about this word
Synonyms and related words
Explore this word