1670s, originally a word for soldiers "who were dexterous in flinging hand-granados" [Evelyn], from French grenadier (15c.), from Middle French grenade "grenade" (see grenade); later "the tallest and finest men in the regiment" [OED]. Grenades went out of use in 18c., but the name was retained by certain companies of regiments.
Gregorian
Gregory
gremlin
Grenada
grenade
grenadier
grenadine
*gre-no-
Grenoble
Grepo
Greta