What is a Compound Noun?
A compound Noun is a type of noun in which two or more words are combined to give a specific meaning to a thing, place, etc. For example toothpaste, raincoat, bus stop, keyboard, mouse pad, bookshelf, face cream, army tank, cowboy, six-pack, etc.
Mostly in Compound Nouns (words), the first word always describes (refers or indicates) the second word and the second word gives the main idea or purpose.
For example, consider the word “toothbrush” –> (tooth + brush).
Here you can observe that the first word “tooth” describes the second word it is something related to the teeth and the second-word “brush” gives a clear purpose or idea.
The same thing goes for the toothpaste also –> (tooth + paste).
Also Read: Noun Definition and Examples | Best English Guide 2025
Types of Compound Nouns
Usually, Compound Noun is categorised into three types. Those are,
- Closed (or) solid (or) single word — no spaces and hyphens.
- Open (or) spaced (or) two words — Only spaces and no hyphens.
- Hyphenated words — Only hyphens and no spaces.
Closed/Solid/Single Words
The words which don’t have any spaces or hyphens between them are called as “Closed Word”. Examples are suitcase, crosswords, smartphone, keyboard, haircut, toothbrush, helipad, etc.
You can observe that the above-given words don’t have any spaces or hyphens between them.
Open/Spaced/two words
The words which have spaces but don’t have hyphens between them are called “Open Words”. Examples are School bell, post office, formal shoes, speed breaker, ice cream, plastic bag, etc.
Since these words don’t have hyphens but have space between them.
Hyphenated Words
The words which have hyphens between them are called “Hyphenated Words” (simply called “hyphen words”). These words don’t have spaces between them because hyphens are used in the spaces.
Examples are son-in-law, t-shirt, mother-in-law, e-mail, up-to-date, co-operation, good-looking, etc.
Rules of Compound Noun
The combined words which are used in Compound Noun can have various types of forms (parts of speech) like,
- noun + noun
- adjective + noun
- verb (-ing) + noun
- verb + preposition
- noun + prepositional phrase
- preposition + noun
- noun + adjective
| POS 1 | + POS 2 | Example |
| noun | noun | raincoat |
| adjective | noun | smartphone |
| verb | noun | running shoes |
| verb | preposition | check-out |
| noun | prepositional phrase | son-in-law |
| preposition | noun | underground |
| noun | adjective | successful |
Plural Forms of Compound Noun
Usually, Compound Nouns have two forms. That is Singular Compound Nouns and Plural Compound Nouns.
Singular Compound Noun refers to a thing, place, etc., whereas Plural Compound Noun refers to more than one thing, place, etc.
Now let us see the examples of these forms given in the table below.
| Singular Compound Noun | Plural Compound Noun |
| bus stop | bus stops |
| ice cream | ice creams |
| paper clip | paper clips |
| waterfall | waterfalls |
| movie ticket | movie tickets |
| radio wave | radio waves |
| formal shoe | formal shoes |
| bookshelf | bookshelves |
| banana leaf | banana leaves |
| butterfly | butterflies |
| brother-in-law | brothers-in-law |
| father-in-law | fathers-in-law |
Some important points that you need to remember:
- If you want to make a word Plural, then you need to add “-s” to the base word (mostly the second word).
- If the words are ending with -s, -ss, -ch, -x, -f, and -o, then you need to add “-es” to the base word.
- For hyphenated words, you need to add “-s” to the base word. Don’t get confused for some words like father-in-law, mother-in-law, etc because their plurals are fathers-in-law and mothers-in-law.
Example Statement:
- Incorrect: Two of my mother-in-laws stays at my house. (There are two mothers, not two laws)
- Correct: Two of my mothers-in-law stays at my house.
- If the words of the Compound Noun are in the form of Noun+adjective, then you can add “-s” or “-es” to noun or adjective as per the usage.
For example, consider the below table.
| Singular Form | PF (Noun) | (or) | PF (Adj) |
| glassful | glassesful | or | glassfuls |
| spoonful | spoonsful | or | spoonfuls |
| handful | handsful | or | handfuls |
| bucketful | bucketsful | or | bucketfuls |
So, you can see that Plural form for hyphenated words can be used in both ways. You can consider plural form of noun or adjective because both of them are acceptable.
But we recommend you to use only one type of words (your choice – either plural form of noun or adjective) for the entire sentence or paragraphs.
Quiz Time! (Test your knowledge here)
Summary: (What is Compound Noun?)
- The combined words which represent a thing, animal, etc are called Compound nouns. Examples are paperclips, coloured pencils, electric wire, cold drinks, etc.
- The Compound Nouns are classified into three types. Those are Closed words, Open words and hyphened words.
- The Compound Noun can have both Singular and Plural forms.
If you are interested in learning more, then you can refer to Wikipedia by clicking here.
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