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.

---

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.

---

add ¹ 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

---

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 ² British  

abbreviation

1. attention deficit disorder

---

ADD Scientific  

1. Abbreviation of attention deficit disorder

---

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

Example Sentences

That adjustment increases the amount that Nasdaq 100 index funds must buy when they add the new issue to their holdings, after the 15th day of trading.

From Barron's • Apr. 1, 2026

My most important bit of advice is don’t add A.I. just because it’s a shiny little button.

From Slate • Apr. 1, 2026

The company is balancing its expansion strategy between China and its overseas markets, eyeing Abu Dhabi, Dubai and Riyadh as its near-term international growth engines, they add.

From The Wall Street Journal • Apr. 1, 2026

Initially Garcia, an accountant with “Dancing with the Stars,” applied to add an ADU to his property but changed his mind because of the cost.

From Los Angeles Times • Apr. 1, 2026

“I bet you miss her a lot,” I add.

From "The Wrong Way Home" by Kate O’Shaughnessy

Related Words

• boost
• continue
• include
• reply