semi-

/sɛmi//sɛmaɪ/

prefix

half

“semi-invalid.”

Similar
half-hemi-demi-quasi--ish
OriginLatin sēmi- ← Proto-Indo-European *sēmi →
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Meanings

prefix

alternative sem-

  1. half

    semi-invalid.

    Synonyms: half-, hemi-, demi-

  2. partial, incomplete

    Synonyms: demi-

  3. somewhat, rather, quasi-

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

    1994, Eric Bogosian, Pounding nails in the floor with my forehead

    Synonyms: quasi-, -ish

Synonyms & antonyms

prefixhalf

Similar
half-hemi-demi-

prefixpartial, incomplete

Similar
demi-

prefixsomewhat, rather, quasi-

Similar
quasi--ish
Also see
demi-fractionalhalfhalf-hemi-partialpartitepene-quasi-

Origin

  1. Proto-Indo-European*sem-
  2. Proto-Indo-European*sēmi
  3. Latinsēmi-
  4. Englishsemi-

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

More words from Latin, Proto-Indo-European

Full word history & related roots →

Translations

Bulgarian полу-
  • полу- (polu-)half (prefix) — see also half-, hemi-, demi-
Catalan semi-
  • semi-half (prefix) — see also half-, hemi-, demi-
Chinese Mandarin 半-
  • 半- (bàn-)half (prefix) — see also half-, hemi-, demi-
Czech semi-
  • semi-half (prefix) — see also half-, hemi-, demi-
Finnish puoli-, semi-
  • puoli-half (prefix) — see also half-, hemi-, demi-
  • semi-half (prefix) — see also half-, hemi-, demi-
French semi-, demi-
  • semi-half (prefix) — see also half-, hemi-, demi-
  • demi-half (prefix) — see also half-, hemi-, demi-
  • à moitiéhalf (prefix) — see also half-, hemi-, demi-
German halb, semi-
  • halbhalf (prefix) — see also half-, hemi-, demi-
  • semi-half (prefix) — see also half-, hemi-, demi-
Greek ημι-
  • ημι- (imi-)half (prefix) — see also half-, hemi-, demi-
Hebrew חצי־, סמי־
  • חצי־ (khatsí-)half (prefix) — see also half-, hemi-, demi-
  • סמי־ (sémi-)half (prefix) — see also half-, hemi-, demi-
Hungarian szemi-, fél-
  • szemi-half (prefix) — see also half-, hemi-, demi-
  • fél-half (prefix) — see also half-, hemi-, demi-
  • félig-half (prefix) — see also half-, hemi-, demi-
Irish leath-
  • leath-half (prefix) — see also half-, hemi-, demi-
Italian semi-, mezzo-
  • semi-half (prefix) — see also half-, hemi-, demi-
  • mezzo-half (prefix) — see also half-, hemi-, demi-
Japanese 半-
  • 半- (han-)half (prefix) — see also half-, hemi-, demi-
Korean 반-
  • 반- (ban-)half (prefix) — see also half-, hemi-, demi-
Latin semi-
  • semi-half (prefix) — see also half-, hemi-, demi-
Malay semi-
  • semi-half (prefix) — see also half-, hemi-, demi-
Norwegian halv-
  • halv-half (prefix) — see also half-, hemi-, demi-
Persian نیم
  • نیم (nim-)half (prefix) — see also half-, hemi-, demi-
Polish pół-
  • pół-half (prefix) — see also half-, hemi-, demi-
Portuguese semi-
  • semi-half (prefix) — see also half-, hemi-, demi-
Punjabi ਅਧ-
  • ਅਧ- (adha-)half (prefix) — see also half-, hemi-, demi-
Romanian semi-, demi-
  • semi-half (prefix) — see also half-, hemi-, demi-
  • demi-half (prefix) — see also half-, hemi-, demi-
  • emi-half (prefix) — see also half-, hemi-, demi-
  • hemi-half (prefix) — see also half-, hemi-, demi-
Russian полу-, семи-
  • полу- (polu-)half (prefix) — see also half-, hemi-, demi-
  • семи- (semi-)half (prefix) — see also half-, hemi-, demi-
Spanish semi-, hemi-
  • semi-half (prefix) — see also half-, hemi-, demi-
  • hemi-half (prefix) — see also half-, hemi-, demi-
Swedish halv-
  • halv-half (prefix) — see also half-, hemi-, demi-
Turkish yarı
  • yarıhalf (prefix) — see also half-, hemi-, demi-
Cite this entry
APA

semi-. (n.d.). In WatkinsX Dictionary. Retrieved November 2, 2026, from https://dictionary.watkinsx.com/word/semi-

MLA

“semi-.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/semi-. Accessed November 2, 2026.

Chicago

WatkinsX Dictionary, s.v. “semi-,” accessed November 2, 2026, https://dictionary.watkinsx.com/word/semi-.

Source: semi- on Wiktionary, CC BY-SA 4.0.