by 1967, American English, probably from Italian grano "grain," or granular, with commercial suffix -ola. Earlier, with a capital G-, it was a proprietary name (reg. 1886 by W.K. Kellogg, in use into early 20c.) for a kind of breakfast cereal.
grange
granger
granite
granitic
granny
granola
grant
grantee
grantor
granular
granulate