Bya

symbol

symbol ·Rare ·Advanced level

Definitions

Symbol
  1. 1
    Abbreviation of billion years ago (A symbol for a unit of measure.); Synonym of Gya (“billion years ago (short scale): 10⁹ years ago”). usually

    "The first (oldest) unit of time is the Precambrian Supereon, which covers much of Earth's history from its origins roughly 4.55 bya to 545 mya. Very primitive, one-celled life-forms arose as early as 4.0 bya and near the end of the era (570 mya) the oldest known fossils of multi-celled organisms appear."

  2. 2
    Alternative spelling of bya (“billion years ago”).; Alternative spelling of bya (“billion years ago (short scale): 10⁹ years ago”). alt-of, alternative, usually
  3. 3
    Alternative spelling of bya (“billion years ago”).; Alternative spelling of bya (“billion years ago (short scale): 10⁹ years ago”). alt-of, alternative, usually
  4. 4
    Abbreviation of billion years ago (A symbol for a unit of measure.); billion years ago (long scale):10¹² years ago: a trillion years ago (short scale). dated, uncommon
  5. 5
    Alternative spelling of bya (“billion years ago”).; Alternative spelling of bya (“billion years ago (long scale):10¹² years ago: a trillion years ago (short scale)”). alt-of, alternative, dated, uncommon
Show 1 more definition
  1. 6
    Alternative spelling of bya (“billion years ago”).; Alternative spelling of bya (“billion years ago (long scale):10¹² years ago: a trillion years ago (short scale)”). alt-of, alternative, dated, uncommon

Synonyms

All synonyms
gya

Example

More examples

"The first (oldest) unit of time is the Precambrian Supereon, which covers much of Earth's history from its origins roughly 4.55 bya to 545 mya. Very primitive, one-celled life-forms arose as early as 4.0 bya and near the end of the era (570 mya) the oldest known fossils of multi-celled organisms appear."

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