What does numberable mean?
Numberable means able to be counted, numbered, or placed in a systematic order. In ordinary use, it describes tangible or abstract things that can be assigned numbers, such as objects, quantities, or entries in a list. Its most distinctive use is in mathematics and set theory, where a numberable set is one whose members can be matched one-to-one with the natural numbers. This definition does not restrict numberable sets to finite collections: an infinite set can also be numberable when a reliable correspondence with the natural numbers exists. The word is more formal and less common than countable, which is the usual term in grammar for nouns that can be counted and have a plural. Numberable is nevertheless useful when the emphasis is on numbering or enumeration rather than grammatical countability, or when discussing the technical concept now commonly called countability.
adjectiveCapable of being counted or assigned a number. In mathematics, a numberable set is one whose elements can be placed in one-to-one correspondence with the natural numbers, so it may be finite or infinite.
- Able to be counted, numbered, or enumerated.
- In set theory, admitting a one-to-one correspondence with the natural numbers, whether finite or infinite.
"The museum catalogued the numberable objects in the collection according to date and material."
"Each of the numberable items was assigned a reference code."
"The set of all finite binary strings is numberable even though it is infinite."
The mathematical surprise is that an infinite set can still be numberable if its elements can be matched one-to-one with the natural numbers.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does numberable come from?
Numberable was formed in English by combining number with the suffix -able, meaning “able to be” or “capable of being.” Number comes through Old French from Latin numerus, a root also preserved in numeral, numerous, and enumerate. The mathematical sense developed alongside the study of countable and uncountable sets in the modern period.
Related word forms
How numberable is actually used
This is a formal and comparatively uncommon word. In everyday grammar, countable is much more usual; numberable is especially associated with mathematics, logic, and discussions of enumeration.
Easily confused with numberable
Countable commonly describes a noun that can be counted or has a plural, whereas numberable focuses more broadly on something being capable of enumeration or assignment to a number.