Subitize

//ˈsʌbɪtaɪz// verb

verb ·Rare ·Advanced level

Definitions

Verb
  1. 1
    To judge (the number of objects in a group) rapidly, accurately and confidently without counting them. intransitive, transitive

    "Previous researchers have noted a similarity between the set sizes that adults can estimate rapidly, or subitize, and the set sizes that infants can discriminate: both are less than five items. This similarity has led some to suggest that subitizing is […]"

Example

More examples

"Previous researchers have noted a similarity between the set sizes that adults can estimate rapidly, or subitize, and the set sizes that infants can discriminate: both are less than five items. This similarity has led some to suggest that subitizing is […]"

Etymology

From Latin subitus (“sudden; unexpected”) + -ize, from the feeling of immediately knowing the number of items present.

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