delta1

 
Pronunciation: /ˈdɛltə/

noun

  • 1the fourth letter of the Greek alphabet (Δ, δ), transliterated as ‘d’.
  • British a fourth-class mark given for an essay, examination paper, or other piece of work.
  • [as modifier] the fourth in a series of items, categories, etc.: delta hepatitis
  • (Delta) [followed by Latin genitive] Astronomy the fourth (usually fourth-brightest) star in a constellation: Delta Cephei
  • 2a code word representing the letter D, used in radio communication.
  • 3 (also delta connection) a triangular arrangement of electrical three-phase windings.

symbol

  • (δ) Mathematics variation of a variable or function.
  • (Δ) Mathematics a finite increment.
  • (δ) Astronomy declination.

Origin:

Greek, from Phoenician daleth