weather side vs weatherboard

weather side and weatherboard both are nouns.

Word	Noun	Adjective	Verb	Adverb
weather side	Yes	No	No	No
weatherboard	Yes	No	No	No

As nouns, weather side and weatherboard are synonyms defined as:

Other synonyms of weather side include windward side.

weather side (noun)	weatherboard (noun)
the side toward the wind	the side toward the wind
	a long thin board with one edge thicker than the other; used as siding by lapping one board over the board below