riptide vs rip current

riptide and rip current both are nouns.

Word	Noun	Adjective	Verb	Adverb
riptide	Yes	No	No	No
rip current	Yes	No	No	No

As nouns, riptide and rip current are synonyms defined as:

riptide and rip current: a strong surface current flowing outwards from a shore

riptide (noun)	rip current (noun)
a strong surface current flowing outwards from a shore	a strong surface current flowing outwards from a shore
a stretch of turbulent water in a river or the sea caused by one current flowing into or across another current