Billionth

//ˈbɪl.i.ənθ// adj, noun

adj, noun ·Rare ·Advanced level

Definitions

Noun
  1. 1
    The person or thing in the billionth position.
  2. 2
    one part in a billion equal parts wordnet
  3. 3
    One of a billion equal parts of a whole.

    "That is an extraordinary achievement for a spiky ball of genetic material coated in fatty chemicals called lipids, and which measures 80 billionths of a metre in diameter. Humanity has been brought low by a very humble assailant."

  4. 4
    position 1,000,000,000 in a countable series of things wordnet
Adjective
  1. 1
    The ordinal form of the number one billion. not-comparable
Adjective
  1. 1
    the ordinal number of one billion in counting order wordnet

Synonyms

All synonyms
one billionthone-billionthordinal

Example

More examples

"Chilling atoms to within one ten billionth of a degree above 0 Kelvin causes them to slow down significantly, making them easier to study."

Etymology

From billion + -th (ordinal suffix).

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Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.