Delta

How to spell delta

5 letters · 2 syllables

How to pronounce delta

Say the part in capitals loudest.

What does delta mean?

1. nounA triangular area of low, fertile land where a river splits into channels and deposits silt as it meets the sea.
2. nounThe fourth letter of the Greek alphabet, written as a triangle in its capital form.
3. nounA difference or change between two values or states, often used informally in science, engineering, and finance.

Delta in a sentence

• The delta of the Nile spreads into a fan of fertile farmland.

• The fraternity name began with the letter delta.

• Engineers measured the temperature delta between the inlet and the outlet.

• Flooding regularly reshapes the channels across the river delta.

• In the phonetic alphabet, the word for the letter D is delta.

• The report focused on the delta in sales from one quarter to the next.

Where does delta come from?

Language of origin: Greek

Delta is the name of the fourth letter of the Greek alphabet, written in capital form as a triangle. The Greeks took both the letter and its name from the Phoenician letter daleth, which literally meant 'door' or 'tent flap' and was drawn as a rough triangle. The geographical sense came from the historian Herodotus in the fifth century BC, who looked at the triangular spread of silt where the Nile fans out into the sea and remarked that it resembled the capital letter delta; the comparison stuck, and 'delta' became the standard word for any such river mouth. Much later, mathematicians and scientists borrowed the same letter to stand for change or difference, since the symbol was a handy shorthand. Because the word is simply the Greek letter's name carried whole into English, it keeps its plain spelling with no awkward traps.

How the word is built

• delta (the fourth letter of the Greek alphabet, written as a triangle); no English prefix or suffix is added