delta

/ˈdɛltə/
noun
  1. A landform at the mouth of a river where it splits into smaller channels and deposits sediment, often shaped like a triangle.
    • The Mississippi River delta is slowly growing as sediment builds up.
    • Many birds nest in the wetlands of the river delta.
    • The Nile Delta is one of the most fertile regions in Egypt.
  2. The fourth letter of the Greek alphabet (Δ, δ).
    • The symbol for delta looks like a triangle.
    • Delta is the fourth letter of the Greek alphabet.
    • In math class, we used the Greek letter delta to represent change.
  3. A change or difference in a quantity, especially in mathematics or science.
    • In physics, delta often stands for the change in velocity.
    • We calculated the delta of the stock price over the past month.
    • The delta in temperature between day and night was 15 degrees.
  4. A code word for the letter D in radio communication.
    • In the NATO phonetic alphabet, 'Delta' stands for the letter D.
    • The operator spelled the call sign as 'Delta, Echo, Alpha.'
    • The pilot radioed 'Delta' to confirm the runway designation.
Synonyms
What does "delta" mean? | whatsthatwordmean | whatsthatwordmean