ebb

(noun) a gradual decline (in size or strength or power or number). Synonyms: ebbing, wane.

(noun) the outward flow of the tide. Synonyms: reflux.

(verb) flow back or recede. Synonyms: ebb away, ebb down, ebb out, ebb off. Example: "The tides ebbed at noon."

(verb) hem in fish with stakes and nets so as to prevent them from going back into the sea with the ebb.

(verb) fall away or decline. Example: "The patient's strength ebbed away."