What is a "concrete noun"?

A Concrete Noun is a word that signifies something that can be seen, heard and touched in the real world. For example; table, lamp, desk, and pen, are all concrete nouns.   However in contrast to this, there is the Abstract Noun. An Abrstact Noun is a word that signifies something that cannot necessarily be seen, heard or touched. This can be something that does not exist in the physical world. For example; love, hope, intelligence, and fear, are all abstract nouns.