Bi-

//baɪ-// prefix

prefix ·Common ·High school level

Definitions

Prefix
  1. 1
    Two in number. morpheme

    "biarticular"

  2. 2
    Alternative form of bio-. alt-of, alternative, before-vowel, morpheme

    "biont"

  3. 3
    Having or possessing two of the root word's quality. morpheme

    "biangular"

  4. 4
    Both: referring to two as a set. morpheme

    "biacetabular"

  5. 5
    Being different in two ways with respect to the root. morpheme

    "biadjoint"

Show 8 more definitions
  1. 6
    Forked, divided by two, halved; (chemistry, proscribed) half morpheme

    "bifurcate"

  2. 7
    Double, twofold. morpheme

    "bialgebroid"

  3. 8
    Bisexual, relating to bisexuality. morpheme

    "bicentric"

  4. 9
    Bilateral, on both sides of the body. morpheme

    "biconcave"

  5. 10
    Twice. morpheme

    "biannual"

  6. 11
    Every two; a rate of once every two. morpheme

    "biannual"

  7. 12
    A pair of; composed of two. morpheme

    "bibrow"

  8. 13
    Used for the digit two to form systematic element names of elements whose existence has been predicted, and which have not yet been given a trivial name. morpheme

    "un- (“1”) + bi- (“2”) + un- (“1”) + -ium (element suffix) → unbiunium (“element 121”)"

Synonyms

All synonyms

Example

More examples

"un- (“1”) + bi- (“2”) + un- (“1”) + -ium (element suffix) → unbiunium (“element 121”)"

Etymology

Etymology 1

PIE word *dwóh₁ Borrowed from Latin bi-, from Proto-Italic *dwi-, from Proto-Indo-European *dwi-. Doublet of twi- and di-.

Etymology 2

From Ancient Greek βίος (bíos, “life”).

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.