ground swell

English Thesaurus

1. a broad and deep undulation of the ocean (noun.event)

hypernym	:	crestless wave, swell,
definition	:	the undulating movement of the surface of the open sea (noun.event)

2. an obvious change of public opinion or political sentiment that occurs without leadership or overt expression (noun.event)

hypernym	:	transition,
definition	:	a change from one place or state or subject or stage to another (noun.event)