hurdle race vs hurdles

hurdle race and hurdles both are nouns.

Word	Noun	Adjective	Verb	Adverb
hurdle race	Yes	No	No	No
hurdles	Yes	No	No	No

As nouns, hurdle race and hurdles are synonyms defined as:

hurdle race and hurdles: a footrace in which contestants must negotiate a series of hurdles

Other synonyms of hurdle race include hurdling.

hurdle race (noun)	hurdles (noun)
a footrace in which contestants must negotiate a series of hurdles	a footrace in which contestants must negotiate a series of hurdles