rising tide vs flood tide

rising tide and flood tide both are nouns.

Word	Noun	Adjective	Verb	Adverb
rising tide	Yes	No	No	No
flood tide	Yes	No	No	No

As nouns, rising tide and flood tide are synonyms defined as:

rising tide and flood tide: the occurrence of incoming water (between a low tide and the following high tide)

Other synonyms of rising tide include flood.

rising tide (noun)	flood tide (noun)
the occurrence of incoming water (between a low tide and the following high tide)	the occurrence of incoming water (between a low tide and the following high tide)
	the highest point of anything conceived of as growing or developing or unfolding