As adjectives the difference between grainiest and rainiest
is that grainiest is superlative of grainy while rainiest is superlative of rainy.
grainiest
English
Adjective
(head)
(grainy)
grainy
English
Adjective
(er)
Resembling grains; granular.
Coarsely ground or gritty.
Anagrams
*
rainiest
English
Adjective
(head)
(rainy)
Anagrams
*
rainy
English
Adjective
(er)
Abounding with rain; wet; showery; as, rainy weather; a rainy day or season.