Standard Lemma guide
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.
prefix
In the International System of Units and other metric systems of units, multiplying the unit to which it is attached by 10−30 (short scale nonillionth or long scale quintillionth).
Definition source: English Wiktionary via Wiktextract
Usage: morpheme
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: quetta-, mul:Q-
History
Blend of q (an arbitrarily chosen initial letter) + Latin decem (“ten”) + -to (to match the final syllable of the SI prefixes from femto- downwards). Coined by Richard J. C. Brown and adopted by the General Conference on Weights and Measures in 2022 as an expansion to the metric prefixes beyond 10^(±24). Some popular unofficial terms already in use were hella-, bronto- and xenna-, but terms beginning with the same letters as existing prefixes were considered undesirable, as were those beginning with common scientific letters such as b or x. Richard J. C. Brown suggested that the new terms begin with r and q, due to their rarity as unit symbols, and that the trends followed by the other prefixes be continued: that they be based on Latin or Greek; that large prefixes end with -a and small prefixes end with -o; that they should be in corresponding large and small pairs; and that the first letters of each prefix should be in reverse alphabetical order (as has been the case for the newer prefixes). He therefore suggested ronna- and ronto- (evoking Ancient Greek ἐννέα (ennéa) and Latin novem (“nine”)), and quecca- and quecto- (evoking Ancient Greek δέκα (déka) and Latin decem (“ten”)), because as 1027 and 1030 when written have nine and ten groups of zeroes, respectively. These were adopted, with quecca- changed to quetta-.
Across languages
16 source translations are retained for this English entry.
