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mantissa

/mænˈtɪsə/noun

mantissa is a noun meaning “The part of a common logarithm after the decimal point, the fractional part of a logarithm” (English Wiktionary, September 2026). It is spelled M-A-N-T-I-S-S-A, and it appears about once in every 16 million words in written English (wordfreq, 2021 data). The plural of mantissa is mantissas or mantissae.

What does mantissa mean?

noun

  1. 1

    obsoleteA minor addition to a text.

  2. 2

    The part of a common logarithm after the decimal point, the fractional part of a logarithm.

  3. 3

    The significand; that part of a floating-point number or number in scientific notation that contains its significant digits.

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).

How do you pronounce mantissa?

  • /mænˈtɪsə/

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: LL-Q1860_(eng)-Wodencafe-mantissa.wav, Wikimedia Commons (author and licence on each file's page).

Forms of mantissa

  • mantissas plural
  • mantissae plural

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).

How common is mantissa?

Mantissa appears about once in every 16 million words in written English, the 119,826th most frequent word form in the list.

Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).

Mantissa in Spanish, French, German and Portuguese

In the sense part of a logarithm after the decimal point:

LanguageWords
Frenchmantisse
GermanMantisse
Portuguesemantissa
Spanishmantisa

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.

Where does mantissa come from?

Borrowed from Latin mantissa, mantīsa, of unknown origin (said by Festus to be a loanword from Etruscan, but it may actually be from Celtic, possibly through Etruscan mediation). Coincidentally, proparoxytone Greek μάντισσα (mántissa) means "female foreteller", as in χαρτομάντισσα (chartomántissa, “cartomancer”) or χειρομάντισσα (cheiromántissa, “chiromancer”).

Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).