trail bike vs dirt bike

trail bike and dirt bike both are nouns.

Word	Noun	Adjective	Verb	Adverb
trail bike	Yes	No	No	No
dirt bike	Yes	No	No	No

As nouns, trail bike and dirt bike are synonyms defined as:

trail bike and dirt bike: a lightweight motorcycle equipped with rugged tires and suspension; an off-road motorcycle designed for riding cross country or over unpaved ground

Other synonyms of trail bike include scrambler.

trail bike (noun)	dirt bike (noun)
a lightweight motorcycle equipped with rugged tires and suspension; an off-road motorcycle designed for riding cross country or over unpaved ground	a lightweight motorcycle equipped with rugged tires and suspension; an off-road motorcycle designed for riding cross country or over unpaved ground