byproduct vs by-product

byproduct and by-product both are nouns.

Word	Noun	Adjective	Verb	Adverb
byproduct	Yes	No	No	No
by-product	Yes	No	No	No

As nouns, byproduct and by-product are synonyms defined as:

byproduct and by-product: a product made during the manufacture of something else

Other synonyms of byproduct include spin-off.

As nouns, byproduct and by-product are synonyms defined as:

byproduct and by-product: a secondary and sometimes unexpected consequence

byproduct (noun)	by-product (noun)
a product made during the manufacture of something else	a product made during the manufacture of something else
a secondary and sometimes unexpected consequence	a secondary and sometimes unexpected consequence