add

¹ American  

[ad] / æd /

verb (used with object)

1. to unite or join so as to increase the number, quantity, size, or importance.

   to add two cups of sugar; to add a postscript to her letter;

   to add insult to injury.

   Synonyms:

   adjoin, attach, append, affix

2. to find the sum of (often followed byup ).

   Add this column of figures.

   Add up the grocery bills.

   Synonyms:

   sum, total

3. to say or write further.

4. to include (usually followed byin ).

   Don't forget to add in the tip.

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verb (used without object)

1. to perform the arithmetic operation of addition.

   children learning to add and subtract.

2. to be or serve as an addition (usually followed byto ).

   His illness added to the family's troubles.

noun

1. Journalism. copy added to a completed story.

verb phrase

1. add up to to signify; indicate.

   The evidence adds up to a case of murder.

idioms

1. add up,

   1. to make the desired, expected, or correct total.

      These figures don't add up right.

   2. to seem reasonable or consistent; be in harmony or accord.

      Some aspects of the story didn't add up.

ADD ² American  

[ey-dee-dee] / ˈeɪˈdiˈdi /

abbreviation

1. attention deficit disorder: the inattentive subtype of ADHD, usually marked by distractibility and difficulties with executive function.

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ADD ¹ British  

abbreviation

1. attention deficit disorder

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add ² British  

/ æd /

verb

1. to combine (two or more numbers or quantities) by addition

2. to increase (a number or quantity) by another number or quantity using addition

3. to join (something) to something else in order to increase the size, quantity, effect, or scope; unite (with)

   to add insult to injury

4. to have an extra and increased effect (on)

   her illness added to his worries

5. (tr) to say or write further

6. to include

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noun

1. informal an instance of adding someone to one's list of contacts on a social networking site, esp MySpace

   Thanks for the add!

ADD Scientific  

1. Abbreviation of attention deficit disorder

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Other Word Forms

• addable adjective
• addedly adverb
• addible adjective
• misadd verb
• readd verb (used with object)
• unaddable adjective
• unadded adjective
• unaddible adjective

Etymology

Origin of add¹

First recorded in 1325–75; Middle English adden, from Latin addere, equivalent to ad- ad- + -dere “to put” (combining form; do ¹ )

Origin of ADD²

First recorded in 1975–80

Explanation

When you add, you join two or more things together. If you add on to your summer cottage, you build an extra room that's connected to your existing house. If your boss adds ten dollars to your paycheck, she gives you the money in addition to, or on top of, your salary. And when you add a column of numbers, you combine each one in the list until you get a final answer. You might verbally add something by making one last statement: "I'd like to add that I can't wait to visit again!" The Latin root is addere, "add to, join, or attach."

Example Sentences

The chain, pleased with last year’s sales, plans to add up to 20 new stores in 2026.

From Los Angeles Times • Apr. 12, 2026

"Speed is the most important thing but you only get three tries in each event and you need to do well in every event as they add the times together," she said.

From BBC • Apr. 11, 2026

“This was part of a broader strategy to add capacity and competition,” he said.

From The Wall Street Journal • Apr. 10, 2026

That can add $20 or more to the cost.

From MarketWatch • Apr. 10, 2026

To add a dog to a team anywhere on the trail was against the rules.

From "Black Star, Bright Dawn" by Scott O'Dell

Related Words

• boost
• continue
• include
• reply