Is a stream a proper noun?

Answer 1

No, stream is a common noun, a singular, concrete noun. Example sentence:

"They threw pebbles at the stream, attempting to make them skip across the water."

Stream is a proper noun only when used in the name of something such as Valley Stream NY or Airstream, Inc. Example sentence:

"They threw pebbles at the Koasha Stream, attempting to make them skip across the water."

Stream is also a verb. Example Sentence:

The exiting crowd will stream accross the street so we will need traffic control on duty.

Answer 2

No, "stream" is not a proper noun. It is a common noun that refers to a flowing body of water. Proper nouns are specific names of people, places, or things, usually capitalized.