windward side vs weatherboard

windward side and weatherboard both are nouns.

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

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

Other synonyms of windward side include weather side.

windward 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