Delta Meaning: Here’s What It Means and How to Use It

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Between one of America’s most prestigious airlines and the coronavirus strain that’s currently plaguing the world, there’s no denying that you haven’t come across the word delta before — but what does it mean? Where did it come from? And how can it be used properly in a sentence? 

You have questions, and we have answers. Read on to discover everything you need to know about the word delta, including the definition, origin, and how to use it in a sentence. 

What Is the Definition of Delta?

/ˈdel·tə/ /ˈdeltə/ /ˈdel.tə/ /ˈdɛltə/

Delta is most commonly defined as a flat plain or low area of alluvial deposits that are more often than not shaped like a triangle. 

A delta is at the mouth of some rivers where it then spreads out and splits into several branches (or distributaries) before entering a larger body of water; think here the Nile delta or Mississippi Delta.  

This, however, is just the tip of the iceberg when defining our word of the day, delta.

Commonly used definitions of delta (pronounced del-tuh) include:

  • Delta, used in reference to mathematics, is also defined as a finite increment in a variable: δ or Δ.
  • In aviation, delta or delta formation is an aircraft formation or flying maneuver that results in aircraft flying in the shape of the letter V.
  • In communications, delta is used as a code word in the ICAO spelling alphabet to represent the letter d.
  • In music, delta is a genre of music, more precisely the Delta Blues, which is a style of blues music that comes from the Mississippi Delta. Fun Fact: Delta Blues was one of the earliest styles of blues music.
  • Delta, when used in reference to finance, is a risk metric that ballparks the change in the price of a derivative (for instance, an options contract).
  • Astronomy uses delta to reference a star that is most commonly the fourth brightest star of a constellation. 
  • Delta can also be used to reference an object that is in the shape of an equilateral triangle. 

What Is the Word Origin of Delta?

Delta — the name of the 4th letter of the Greek alphabet most similar to our letter D, though shaped like a triangle — was first noted in c. 1200. Middle English delta has a Semitic origin with ties to the Hebrew dāleth. 

Ancient Greek historian and geographer Herodotus first used the Greek letter delta as an “alluvial tract,” or “triangular island,” due to the fact of the delta or triangular-shaped mouth of the Nile.

It was not until the 1550s when it was first used in English to apply to the mouth of a river anywhere, not just the Nile, and by 1790 was commonly used as such. 

What Are the Synonyms and Antonyms of Delta?

Now that you have a pretty good understanding of the word delta, let’s open up a thesaurus to take a look at a few synonyms and antonyms, shall we?

In case you forgot from grade school, synonyms are words or expressions that have the same or nearly the same meaning as another word or expression, whereas antonyms are words that have an opposite meaning.   


  • Estuary
  • Natural harbor
  • Shoreline indentation
  • Sea passage
  • Outlet
  • Deltaic
  • Silt
  • Triangle
  • Mouth 
  • Entrance 
  • Hedge ratio
  • Split
  • Trident 
  • Chersonese 
  • Tidal inlet
  • Stretch of water
  • Water mouth
  • Narrow-body of water
  • Alluvial plain
  • Floodplain
  • River mouth
  • Rivulet
  • Tidal plain
  • Delta plain
  • Mere
  • Outfall 


  • Source 
  • Incontinent 
  • Acquisition 

What Are Some Examples of Delta in a Sentence?

By now, you know that our word of the way has more than one meaning, but how can it be used in a sentence? Here are a few sentence examples for you to review:

“Alluvium is the reason why we have remained at the mouth of the river, despite the endless floods, living on this delta has provided for our family for generations.“

“My grandma got sick with the highly contagious delta virus strain when it first emerged two years ago and hasn’t been sick since.”

“Don’t knock it; there are over 450 million people that live, work, and thrive in the world’s major river deltas.” 

“According to many experts, the Delta variant of COVID-19 is a major concern — hence why the FDA is enforcing mask laws and social distancing again.”

“I am flying on Delta — which airline are you going to be on?”

“Did you know that the Delta Force is one of America’s special missions units?”

“I have four dogs that are named Alpha, Bravo, Charlie, and Delta after the military alphabet.”

“The nation’s leading geologists predict that this delta will be fully submerged in the near future, while six islands are already underwater.”

“If you ask me, the worst coronavirus variant was delta.”

What Are Translations of Delta?

Wondering how to say our word of the day in a different language? We’ve got you covered — here are some of the top translations of delta:

  • Chinese (Traditional) — 三角洲, (希臘語字母表的第四個字母)
  • Italian — delta 
  • Ukrainian — дельта
  • German — das Delta
  • Vietnamese — châu thổ, đồng bằng
  • Japanese — 三角州
  • Turkish — delta, bir kaç nehir ve kollarının oluşturduğu nehir yatağ
  • Korean — 삼각주
  • Norwegian — delta, (elve)os 
  • European Portuguese — delta 
  • Spanish — delta 
  • Russian — дельта (реки
  • Thai — ดินดอนสามเหลี่ยมปากแม่น้ำ


Just remember, while the word delta may have various meanings, it is most commonly defined as a triangular mass of sediment or landform at the mouth of a major river that empties into a body of water. 

Delta is named after the fourth letter of the Greek alphabet, which is shaped like a triangle. Astronomy uses delta to reference the fourth brightest star of a constellation. 


Delta definition and meaning | Collins English Dictionary 

What does delta mean? Best 27 Definitions of Delta | Your Dictionary 

Delta Definition & Meaning | Britannica Dictionary