Collective nouns in english contents introduction

2.2. What is an example of a noun
In English grammar, a compound noun (or nominal compound) is a construction made up of two or more nouns that function as a single noun. With somewhat arbitrary spelling rules, compound nouns can be written as separate words like tomato juice, as words linked by hyphens like sister-in-law or as one word like schoolteacher.
A compound noun whose form no longer clearly reveals its origin, such as bonfire or marshall, is sometimes called an amalgamated compound; many place names(or toponyms) are amalgamated compounds — for example, Norwich is the combination of "north" and "village" while Sussex is a combination of "south" and "Saxons.¹"
One interesting aspect of most compounds nouns is that one of the origin words is syntactically dominant. This word, called the headword, grounds the word as a noun, such as the word "chair" in the compound noun "easychair."
A compound noun contains two or more words that join together to make a single noun. A compound noun is a type of compound word that is used to designate a person, place or thing. Compound nouns can be formed in several ways, which is one reason that the writing of these words in English can be tricky.

What Is a Compound Noun?

A compound noun is formed when two words are combined to make a completely new word. This means that the meaning of the new word must be significantly different than either of its parts. For example, a hot dog (or hotdog) - i.e., a type of sausage typically eaten on a bun - may be hot, but it's certainly not a dog. The combination of these two words means something entirely different than the mere combination of the adjective"hot" and the noun "dog," which would refer to an overheated, panting canine. Observe the difference below:

• 
  I would like to eat a hot dog when we go to the county fair.
  
• 
  The hot dog was grateful to find a shady spot for a nap.
  

The first sentence uses "hot dog" as a compound word, but the second does not. The meaning is quite different in each sentence, and English speakers have no trouble telling the difference between pets and food!