sea tangle vs tang

sea tangle and tang both are nouns.

Word	Noun	Adjective	Verb	Adverb
sea tangle	Yes	No	No	No
tang	Yes	No	No	No

As nouns, sea tangle and tang are synonyms defined as:

sea tangle and tang: any of various kelps especially of the genus Laminaria

sea tangle (noun)	tang (noun)
any of various kelps especially of the genus Laminaria	any of various kelps especially of the genus Laminaria
	any of various coarse seaweeds
	brown algae seaweed with serrated edges
	a common rockweed used in preparing kelp and as manure
	a tart spicy quality
	the taste experience when a savoury condiment is taken into the mouth