Del"ta, n. 1. The fourth letter of the Greek alphabet (Δ δ), answering to D. Hence, an object having the shape of the capital Δ.

2. (Elec.) The closed figure produced by connecting three coils or circuits successively, end for end, esp. in a three-phase system; -- often used attributively, as delta winding, delta connection (which see), etc.

Del"ta (?), n.; pl. Deltas (#). [Gr. de`lta, the name of the fourth letter of the Greek alphabet (the capital form of which is Δ, Eng. D), from the Phœnician name of the corresponding letter. The Greeks called the alluvial deposit at the mouth of the Nile, from its shape, the Delta of the Nile.] A tract of land shaped like the letter delta (Δ), especially when the land is alluvial and inclosed between two or more mouths of a river; as, the delta of the Ganges, of the Nile, or of the Mississippi.

Del"ta, n. 1. The fourth letter of the Greek alphabet (Δ δ), answering to D. Hence, an object having the shape of the capital Δ.

2. (Elec.) The closed figure produced by connecting three coils or circuits successively, end for end, esp. in a three-phase system; -- often used attributively, as delta winding, delta connection (which see), etc.

• The name for the fourth letter of the modern Greek alphabet Δ, δ.
  
• The silted triangular mouth of a large river where it empties into a sea or large body of water. Wikipedia has a detailed description.
  
• (Phonetics) δ In the IPA, the symbol that represents the voiced dental fricative, the hard th in the English word father. Usu. represented by the Icelandic eth/edh (ð).
  
• (mathematics) A change in some quantity.
  
• (computing, colloquial) A small but noticeable effect, compare with epsilon.
        This will slow the main code path down, but only by delta.
  
• The letter D in the ICAO spelling alphabet, which assigns words to letters of the alphabet.
  
  Swedish
• Delta; the Greek letter Δ,δ
  
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