different between biennial vs biannual

English

Etymology

Borrowed from Latin bienni(um) (“two-year period”) [from bis, bi- (“twice”) + annus (“year”)] + -al (suffix forming adjectives); surface analysis bi- +? -ennial.

Pronunciation

• IPA^(key): /ba???n??l/
• Rhymes: -?n??l

Adjective

biennial (not comparable)

1. Happening every two years.
2. Lasting for two years.

Synonyms

• biennary (uncommon); biannual (proscribed)

Related terms

• biennium
• biennially
• biannual, semiannual

Translations

Noun

biennial (plural biennials)

1. A plant that requires two years to complete its life-cycle, germinating and growing in its first year, then producing its flowers and fruit in its second year, after which it usually dies
2. An event that happens every two years

Translations

See also

• annual
• perennial

English

Etymology

bi- +? annual.

Pronunciation

• (Received Pronunciation) IPA^(key): /b???anju??l/
• (General American) IPA^(key): /ba??ænju?l/
• Hyphenation: bi?an?nu?al

Adjective

biannual (not comparable)

1. Occurring twice a year; semiannual.
2. (proscribed) Occurring once every two years; biennial.

Usage notes

Although biannual conventionally means twice a year, its conflation with biennial (once every two years) is quite common.

Alternative forms

• bi-annual

Synonyms

• (two times per year): half-yearly, semiannual, twice-yearly
• (every two years): biennial

Derived terms

• biannually

Translations

Noun

biannual (plural biannuals)

1. Something occurring twice each year.