Etymologically
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semi-

This is the current revision of this entry, as edited by bogdan on 24 October 2026 at 18:48. This address is a permanent link to this version.
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Pronunciation

  • Classical: [ˈseː.mɪ][1]
  • Ecclesiastical: [ˈsɛː.mi][1]

Forms

sēmi- [1]

Etymology

It is inherited from Proto-Italic *sēmi-, inherited from Proto-Indo-European *sēm-i (“in one”), originally a locative singular.[2] De Vaan explains the sense as having moved from “(in) one” to “one of two” and then to “half”.[2]

Cognate with Sanskrit सामि (sāmí, “half”), Ancient Greek ἡμι- (hēmi-, “half”), Old English sām- and Old High German sāmi- (“half”).[2][1] De Vaan also compares, with a query, Umbrian sehemu “single, separate?”.[2]

Earliest recorded meaning

It is found from Plautus on,[2] who has sinciput “half a head” and sincipitāmentum.[2]

Semantic evolution

It was prefixed to nouns and adjectives with the sense “half”, sometimes exactly and sometimes loosely,[3] as in sēmideus “demigod” and sēmēsus “half-eaten”.[4] Before a vowel it often lost its ⟨i⟩ (sēmermis, sēmuncia), and before ⟨m⟩ or ⟨l⟩ it could be reduced to sē- (sēlībra, sēmodius).[3][2] Lewis and Short add that it could also stand for “small, thin, light”.[4]

English took it over as the prefix semi-, also used loosely for “partly, almost, imperfect”.[5]

Timeline

Meanings

Prefix

  1. Half-, semi-, demi-: forming nouns and adjectives that are half of something or half so.[3][4]
  2. Loosely, partly, slightly, imperfectly.[3][4]

Word family

References

  1. ^ a b c d Wiktionary, the free dictionary, https://en.wiktionary.org
  2. ^ a b c d e f g h i j de Vaan, Michiel (2008), Etymological Dictionary of Latin and the other Italic Languages, Leiden Indo-European Etymological Dictionary Series 7, Leiden; Boston: Brill
  3. ^ a b c d Glare, P. G. W., ed. (2012), Oxford Latin Dictionary, 2nd ed., Oxford: Oxford University Press
  4. ^ a b c d Lewis, Charlton T.; Short, Charles (1879), A Latin Dictionary, Oxford: Clarendon Press
  5. ^ Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  6. ^ a b c Köbler, Gerhard (2010), Lateinisches Abkunfts- und Wirkungswörterbuch für Altertum und Mittelalter, online ed., koeblergerhard.de