A noun is a word or set of words for a person, place, thing, or idea.

'Doctor', 'coal', and 'beauty' are all nouns.
An example of a countable noun is 'table', and an example of an uncountable noun is 'money'.
In 'safety barrier', the noun 'safety' is being used as a modifier.
In this dictionary the word 'noun' is represented by the letter n.
Examples of proper nouns in English are Joseph, Vienna and the White House.
'Family' and 'flock' are examples of collective nouns.