addition

[uh-dish-uhn]

noun

1. the act or process of adding or uniting.

2. the process of uniting two or more numbers into one sum, represented by the symbol +.

3. the result of adding.

   Synonyms: accession, increment, enlargement, increase

4. something added.

   Synonyms: appendix, supplement, accession, increment, enlargement, increase

5. a wing, room, etc., added to a building, or abutting land added to real estate already owned.

6. Chemistry.,  a reaction in which two or more substances combine to form another compound.

addition

/ əˈdɪʃən /

noun

1. the act, process, or result of adding

2. a person or thing that is added or acquired

3. a mathematical operation in which the sum of two numbers or quantities is calculated. Usually indicated by the symbol +

4. a part added to a building or piece of land; annexe

5. obsolete,  a title following a person's name

6. (adverb) also; as well; besides

7. (preposition) besides; as well as

addition

1. The act, process, or operation of adding two or more numbers to compute their sum.

Other Word Forms

• preaddition noun
• readdition noun

Word History and Origins

Origin of addition¹

First recorded in 1350–1400; Middle English addicio(u)n, from Latin additiōn-, stem of additiō, from addit(us) “added” (past participle of addere “to add”; add ) + -iō -ion

Word History and Origins

Origin of addition¹

C15: from Latin additiōn-, from addere to _add

Idioms and Phrases

Idioms

1. in addition to, as well as; besides.

   In addition to directing the play, she designed most of the scenery.

see in addition.

Synonym Study

Addition, accessory, adjunct, attachment mean something joined onto or used with something else. Addition is the general word, carrying no implication of size, importance, or kind, but merely that of being joined to something previously existing: an addition to an income, to a building, to one's cares. An accessory is a subordinate addition to a more important thing, for the purpose of aiding, completing, ornamenting, etc.: accessories to a costume. An adjunct is a subordinate addition that aids or assists a main thing or person but is often separate: a second machine as an adjunct to the first. An attachment is an accessory part that may be easily connected and removed: a sewing machine attachment for pleating.

Example Sentences

Temperatures in the cockpit of an F1 car can be more than 40C, and drivers are wearing several layers of fireproof clothing in addition to a balaclava and helmet, so overheating is a serious concern.

From BBC

The same is true for the EPA, which has undergone staff cuts and layoffs in addition to a considerable shift in its organizational priorities.

From Los Angeles Times

I knew I had to come, because, in addition to the ghosts and whatever animals have made ESP their home, it houses a massive haunted attraction, Terror Behind the Walls.

From Salon

In addition to the assault, the concert drew criticism for being overcrowded inside and feeling like an unsafe environment.

From Los Angeles Times

In addition to the warnings for wind, there is a yellow Met Office warning for rain across much of Scotland from 12:00 BST to 23:59 Friday.

From BBC

Related Words

• bonus 
• boost 
• enhancement 
• expansion 
• extension 
• supplement 

When To Use

What is a basic definition of addition?

Addition is a mathematical operation in which two or more numbers are combined to equal a greater number. The word addition also refers to the act of adding. More generally, it refers to an increase or boost applied to something. Addition has a few other senses as a noun.Addition is one of math’s basic operations. Two or more numbers are united to result in a greater number, called a sum. The symbol used for addition is +, which is called a plus sign.Real-life examples: Here are some basic examples of addition: 2 + 2 = 4, 17 + 35 = 52, 143 + 64 = 207.Used in a sentence: I’m teaching the kids to use addition to figure out how much money they need to pay for lunch. An addition is something that has been joined or combined with something else to enhance it or provide more to it.Real-life examples: Recipes can be improved or made more flavorful by using additions such as spices. Accessories and decorations are used as additions to things like cars or clothing to make them look nicer or more stylish.Used in a sentence: Paintings and flowers make nice additions to any room. Relatedly, addition can refer to new rooms or wings that are attached to a building.Used in a sentence: The college is planning a new addition to the campus library. Addition is also used to refer to the act or an instance of adding to something or increasing it in some way.Used in a sentence: The roller coaster became much more popular after the addition of exciting music and amazing decorations.