safety isle vs island

safety isle and island both are nouns.

Word	Noun	Adjective	Verb	Adverb
safety isle	Yes	No	No	No
island	Yes	No	No	No

As nouns, island is a hypernym of safety isle; that is, island is a word with a broader meaning than safety isle:

safety isle: a curbed area in a roadway from which traffic is excluded; provides safe area for pedestrians
island: a zone or area resembling an island

safety isle (noun)	island (noun)
a curbed area in a roadway from which traffic is excluded; provides safe area for pedestrians	a zone or area resembling an island
	a land mass (smaller than a continent) that is surrounded by water