Standard Lemma guide

semi-

prefix · 3 senses · updated from the 2026-07-25 local source snapshot

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

Pronunciation

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.

  • /sɛmi/
  • /sɛmaɪ/
  • UK: Recorded audio is listed in the source snapshot.
  • US: Recorded audio is listed in the source snapshot.

1

prefix

Meaning 1

half

Definition source: English Wiktionary via Wiktextract

Usage: morpheme

Examples

  • semi-invalid.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

prefix

Meaning 2

partial, incomplete

Definition source: English Wiktionary via Wiktextract

Usage: morpheme

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

prefix

Meaning 3

somewhat, rather, quasi-

Definition source: English Wiktionary via Wiktextract

Usage: morpheme

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

History

Etymology

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

Across languages

Translations

43 source translations are retained for this English entry.

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