semi-

• sem-

Borrowed from Latin semi- (“half”), from Proto-Indo-European *sēmi/*sēmi-. Cognate to English sam, and to hemi- (via Ancient Greek).

• IPA^(key): /sɛmi/, /sɛmaɪ/

  • Audio (UK):

    (file)

  • Audio (US):

    (file)

semi-

2. half

   semi-invalid.

4. partial, incomplete
6. somewhat, rather, quasi-
   • 1994, Eric Bogosian, Pounding nails in the floor with my forehead:

     Nothing like a nice hot ethnic dish before you go to see that semi-expensive, semi-meaningful Off-Broadway show.

• In British English, the semi- forms are usually hyphenated as evidenced by OED's semi- entries predominantly using hyphen.

• (half): half-, hemi-, demi-
• (partial): demi-
• (somewhat): quasi-, -ish

• semiflat

• “semi-”, in OneLook Dictionary Search.
• “semi-”, in Merriam-Webster.com Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.
• John A. Simpson and Edmund S. C. Weiner, editors (1989), “semi-”, in The Oxford English Dictionary, 2nd edition, Oxford: Clarendon Press, →ISBN.

• EMIs, ESMI, IMEs, MSIE, Meis, Sime, eSIM, mise

Borrowed from Latin sēmi-.

• IPA^(key): (Central, Balearic) [ˌsɛ.mi]
• IPA^(key): (Valencia) [ˌse.mi]

semi-

1. semi-

• “semi-”, in Diccionari de la llengua catalana [Dictionary of the Catalan Language] (in Catalan), second edition, Institute of Catalan Studies [Catalan: Institut d'Estudis Catalans], April 2007
• “semi-”, in Gran Diccionari de la Llengua Catalana, Grup Enciclopèdia Catalana, 2026
• “semi-” in Diccionari normatiu valencià, Acadèmia Valenciana de la Llengua.
• Alcover, Antoni Maria; Moll, Francesc de Borja (1963), “semi-”, in Diccionari català-valencià-balear (in Catalan)

• IPA^(key): [sɛmɪ ]

semi-

1. semi-

   ‎semi- + ‎finále → ‎semifinále

• “semi-”, in Příruční slovník jazyka českého (in Czech), 1935–1957
• “semi-”, in Slovník spisovného jazyka českého (in Czech), 1960–1971, 1989
• semi- in Slovník afixů užívaných v češtině, 2017

Learned borrowing from Latin semi-.

• IPA^(key): /ˈsemi-/, [ˈs̠e̞mi-]

semi-

1. (chiefly in loanwords) half-, semi-, demi-

   Synonym: puoli-

• semi

• “semi-”, in Kielitoimiston sanakirja [Dictionary of Contemporary Finnish]‎^[1] (in Finnish) (online dictionary, continuously updated), Kotimaisten kielten keskuksen verkkojulkaisuja 35, Helsinki: Kotimaisten kielten tutkimuskeskus (Institute for the Languages of Finland), 2004–, retrieved 3 July 2023

From Latin sēmi-.

• IPA^(key): /sə.mi/

• Audio (Canada (Shawinigan)):

  (file)

semi-

1. semi-, demi-, half-

From Latin sēmi-.

• IPA^(key): /ˈzeːmi/

• Audio (Germany (Berlin)):

  (file)

semi-

1. (fairly rare, learned) semi-, half-

   Synonym: halb-

   ‎semi- + ‎automatisch (“automatic”) → ‎semiautomatisch (“semi-automatic”)

2. (slang or colloquial) not very, hardly [since ca. 2000]

   ‎semi- + ‎gut (“good”) → ‎semigut (“not very good, rather bad”)

• In the literal sense, this prefix is productive only with Latinate stems, though halb- is much more common even with these (e.g. halbautomatisch).
• In the slang sense, to the contrary, it is productive mostly with native adjectives. These may also be spelt with a hyphen (semi-gut). They are often preceded by an adverb such as nur or eher.

From Latin sēmi-, from Proto-Indo-European *sēmi (“half”).

• IPA^(key): /se.mi/
• Hyphenation: se‧mi-

semi-

1. semi-, demi-, half-

• mesi, mise

• sē- (in sēlībra, sēmodius)
• sēm- (before vowels, e.g. sēmis)
• sin- (in sinciput)

From Proto-Indo-European *sēmi-. Cognate with Sanskrit सामि (sāmí), Ancient Greek ἡμι- (hēmi-), Old High German sami-.

• (Classical Latin) IPA^(key): [ˈseː.mɪ]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈsɛː.mi]

sēmi-

1. half

• → English: semi-, semi
• → French: semi-
• → Italian: semi-
• → Portuguese: semi-
• → Spanish: semi-

• “semi-”, in Charlton T. Lewis and Charles Short (1879), A Latin Dictionary, Oxford: Clarendon Press
• “semi-”, in Charlton T. Lewis (1891), An Elementary Latin Dictionary, New York: Harper & Brothers

From Latin sēmi-.

• Hyphenation: se‧mi

semi-

1. semi- (half)
2. semi- (partially)

• “semi-”, in Dicionário Aulete Digital (in Portuguese), Rio de Janeiro: Lexikon Editora Digital, 2008–2026
• “semi-”, in Dicionário Priberam da Língua Portuguesa (in Portuguese), Lisbon: Priberam, 2008–2026

From Latin sēmi-.

• IPA^(key): /semi/ [se.mi]
• Syllabification: se‧mi-

semi-

1. semi- (half)
2. semi- (partially)

• sesqui-

• “semi-”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025

From Latin semi-.

semi-

1. semi-, half-

   Synonym: halv-

• “semi-”, in Svenska Akademiens ordböcker [Dictionaries of the Swedish Academy] (in Swedish)