Is outside a proper noun

Answer 1

No, the noun 'outside' is a common noun, a general word for the external surface of something; a general word for the space beyond an enclosure or boundary; a word for the outside of anything.

A proper noun is the name or title of a specific person, place, or thing; for example, Outside Magazine or the Outside Inn in Waterbury, CT.

The word 'outside' is also an adjective, an adverb, and a preposition.