Meanings
- not comparablemathematicsCapable of being assigned a bijection to the natural numbers. Applied to sets which are not finite, but have a one-to-one mapping to the natural numbers.
The empty set is not denumerable because it is finite; the rational numbers are, surprisingly, denumerable because every possible fraction can be assigned a natural number and vice versa.
Synonyms: countable, countably infinite
Synonyms & antonyms
adjectiveCapable of being assigned a bijection to the natural numbers. Applied to sets which are not finite, but have a one-to-one mapping to the natural numbers.
More synonyms by meaning
adjectivethat can be counted
Synonym sets from Open English WordNet, CC BY 4.0.
Origin
The word was introduced around the beginning of the 20th century, from Latin denumerō (“to count out”) + -able.
Full word history & related roots →Cite this entry
denumerable. (n.d.). In WatkinsX Dictionary. Retrieved November 2, 2026, from https://dictionary.watkinsx.com/word/denumerable
“denumerable.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/denumerable. Accessed November 2, 2026.
WatkinsX Dictionary, s.v. “denumerable,” accessed November 2, 2026, https://dictionary.watkinsx.com/word/denumerable.
Source: denumerable on Wiktionary, CC BY-SA 4.0.