Compound Noun | Definition, How to Use & Examples
A compound noun is a noun that is made up of two or more words.
We love French fries.
I’m buying flowers for my mother-in-law.
Compound nouns are formed in various ways using many types of words. To make sure you use all compound nouns correctly, try QuillBot’s free Grammar Checker.
What is a compound noun?
A compound noun consists of two or more words that work together as a single noun. These components can be nouns, verbs, adjectives, prepositions, and more. For example, the compound noun “doorstop” is made up of the noun “door” and the verb “stop.”
Compound nouns can be common nouns (e.g., “doorstop”) or proper nouns (e.g., “Anglo-Saxon”). They can be concrete nouns (e.g., “waterfall”) or abstract nouns (e.g., “weekend”).
The components of compound nouns can be combined in a few ways:
- Closed compound nouns do not have a space between components (e.g., “teenager”).
- Hyphenated compound nouns use a hyphen to join their components (e.g., “brother-in-law”).
- Open compound nouns have a space between components (e.g., “fairy tale”).
A compound noun differs from a noun phrase and noun clause, although all three function as nouns. A noun phrase is a group of words with a “head noun” and at least one modifier (e.g., “a large forest”). A noun clause is a dependent clause that has a subject and a verb but cannot stand alone as a sentence (e.g., “what book we will read”).
A portmanteau, on the other hand, is formed from two words whose spellings and meanings are blended into those of the new word. An example is “brunch,” a combination of “breakfast” and “lunch.”
Forming compound nouns
Compound nouns can be formed in a variety of ways, using different types of words as building blocks. Below are some ways they can be formed, plus some examples.
| Compound elements | Examples |
|---|---|
| Noun + noun | Basketball, footprint, blueberry |
| Noun + verb | Snowfall, ghostwrite, airlift |
| Noun + adjective | Sky blue, lime green, duty-free |
| Noun + preposition | Passerby, runner-up, hanger-on |
| Noun + prepositional phrase | Lady-in-waiting, son-in-law, brother in arms |
| Verb + noun | Surfboard, scarecrow, playground |
| Verb + preposition | Lookout, hookup, break-in |
| Adjective + noun | Hot dog, greenhouse, software |
| Adjective + gerund | Dry cleaning, public speaking, Alpine skiing |
| Preposition + noun | Underworld, overcoat, bystander |
| Preposition + verb | Input, outcry, upload |
Compound noun rules
When using compound nouns, there are a few rules to bear in mind.
Pluralization
When pluralizing compound nouns, pluralize the “semantic head,” the part that carries the core meaning. For example:
- “Sister-in-law” becomes “sisters-in-law.”
- “Passerby” becomes “passersby.”
- “Firefighter” becomes “firefighters.”
For example, the most common plural “spoonful” is “spoonfuls.” “Spoonsful” isn’t wrong, but it’s much less commonly used nowadays than its counterpart.
Capitalization
Follow standard capitalization rules when capitalizing compound nouns. If the compound noun is a common noun, only capitalize the first letter when it is the first word in a sentence. If it’s a proper noun, always capitalize all parts of the compound (e.g., “New York”).
I love visiting bookstores in different cities.
Blake is from South Africa.
For hyphenated titles, check your style guide (e.g., APA, MLA, or Chicago), but generally speaking, capitalize the first and other substantial words, but do not capitalize small words like “in” or “of” (e.g., “Editor-in-Chief Anna Smith”).
Stress
In compound nouns, stress typically falls on the first word, which helps distinguish them from noun phrases. Imagine, for example, how you would pronounce “a greenhouse” and “a green house.”
Think about how you would pronounce other compound nouns to get a feel for stress on the first word:
- Smartphone
- Bluebird
- Goldfish
- Carpool
- Clockwise
- Father-in-law
Compound noun examples
Below are more examples of compound nouns, plus a few examples of how some of them may be used in sentences.
Compound nouns for people:
- African-American
- Anglo-Saxon
- Attorney general
- Babysitter
- Bodybuilder
- Bodyguard
- Brother-in-law
- Bus driver
- Ex-husband
- Ex-wife
- Father-in-law
- Firefighter
- French-Canadian
- Godchild
- Godfather
- Godmother
- Grandparent
- Grandchild
- Housekeeper
- Lifeguard
- Mexican-American
- Mother-in-law
- Pickpocket
- Prime minister
- Salesman
- Salesperson
- Secretary-general
- Sister-in-law
- Stepbrother
- Stepfather
- Stepsister
- Stepmother
- Superhero
- Taxi driver
- Vice president
Compound nouns for places:
- Amazon River
- Amusement park
- Bathtub
- Battlefield
- Bermuda Triangle
- Boardwalk
- Bus stop
- City hall
- Country club
- Dead Sea
- Desert island
- Machu Picchu
- Mount Everest
- New York
- Post office
- Schoolyard
- Seashore
- Shopping mall
- Skyscraper
- Snowbank
- Strip mall
- Stronghold
- Swimming pool
I met my stepmother and stepfather at the shopping mall after dropping my letters at the post office.
A French-Canadian came up to me at the bus stop asking for directions to the boardwalk.
Compound nouns for things:
- Alarm clock
- Backpack
- Baseball
- Blackboard
- Cornstalk
- Eggshell
- Forklift
- Handwriting
- Highchair
- Kneecap
- Motorcycle
- Newspaper
- Penknife
- Playground
- Quicksand
- Railway
- Rubber band
- Teaspoon
- Toothbrush
- Toothpick
- Turntable
- Underwear
- Watermark
- Watermelon
- Wheelchair
- Wristwatch
- Warship
Compound nouns for ideas or concepts:
- Brainstorm
- Customer service
- Data analysis
- Fatherhood
- Freedom of speech
- Handmade
- Horsepower
- Lifesaver
- Market research
- Motherhood
- Northeast
- Peer pressure
- Public relations
- Risk management
- Self-esteem
- Social media
- Southwest
- Teamwork
- Time management
- Waterproofing
Louis only packed the essentials: clean underwear, a toothbrush, and the wristwatch that belonged to his grandfather.
Teamwork, time management, and courteous customer service are of the utmost importance in this role.
Frequently asked questions about compound noun
- Is check up a compound noun?
-
Not exactly. “Checkup,” written as one word, is a compound noun that means “an examination.”
“Check up,” written as two words, is a phrasal verb that means “to get information about.” You can check up on someone or something.
Use QuillBot’s free Grammar Checker if you have any doubts about how to use these words.
- Is follow up a compound noun?
-
Not quite. “Follow-up,” written with a hyphen, is a compound noun meaning “a continuation or repetition of something already started.”
“Follow up,” written as two words, is a phrasal verb that means “to pursue or investigate something further.”
QuillBot’s free Grammar Checker can make sure you use these words correctly in your writing.
