Standard Lemma guide

semimajor

adj · 2 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.

  • US: Recorded audio is listed in the source snapshot.

1

adj

Meaning 1

Of or pertaining to the semimajor axis, the long axis of an ellipse

Definition source: English Wiktionary via Wiktextract

Usage: not-comparable

Topics: geometry, mathematics, sciences

Examples

  • a semimajor radius

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

adj

Meaning 2

Less than major, but still significant

Definition source: English Wiktionary via Wiktextract

Usage: not-comparable

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- Proto-Indo-European *méǵh2s Proto-Indo-European *-yōs Proto-Indo-European *méǵh2yōs Proto-Italic *majjōs Latin maiorder. Middle English major English major English semimajor From semi- + major.