Compound Noun

A compound noun is a noun that is made up of two or more words. Most compound nouns in English are formed by nouns modified by other nouns or adjectives.

For example:

The words tooth and paste are each nouns in their own right, but if you join them together they form a new word – toothpaste.

The word black is an adjective and board is a noun, but if you join them together they form a new word – blackboard.

In both these example the first word modifies or describes the second word, telling us what kind of object or person it is, or what its purpose is. And the second part identifies the object or person in question.

Compound nouns can also be formed using the following combinations of words:-

Noun    +    Noun    toothpaste
Adjective    +    Noun    monthly ticket
Verb    +    Noun    swimming pool
Preposition    +    Noun    underground
Noun    +    Verb    haircut
Noun    +    Preposition    hanger on
Adjective    +    Verb    dry-cleaning
Preposition    +    Verb    output

The two parts may be written in a number of ways:-

1. Sometimes the two words are joined together.
Example: tooth + paste = toothpaste | bed + room = bedroom

2. Sometimes they are joined using a hyphen.
Example: check-in

3. Sometimes they appear as two separate words.
Example: full moon