starting gate vs barrier

starting gate and barrier both are nouns.

Word	Noun	Adjective	Verb	Adverb
starting gate	Yes	No	No	No
barrier	Yes	No	No	No

As nouns, barrier is a hypernym of starting gate; that is, barrier is a word with a broader meaning than starting gate:

starting gate (noun)	barrier (noun)
a movable barrier on the starting line of a race course	a structure or object that impedes free movement
	any condition that makes it difficult to make progress or to achieve an objective
	anything serving to maintain separation by obstructing vision or access