also borborygmi, "rumbling noise in the bowels," 17c., from Latin borborigmus, from Greek borborygmos, from borboryzein "to have a rumbling in the bowels," imitative.
1580s, "complain in a low voice;" 1590s, "make a low, rumbling sound," from French grommeler "mutter between the teeth" or directly from Middle Dutch grommelen "murmur, mutter, grunt," from grommen "to rumble, growl." Imitative, or perhaps akin to grim (adj.). With unetymological -b- as in mumble. Related: Grumbled; grumbling.
late 14c., "make a deep, heavy, continuous sound," also "move with a rolling, thundering sound," also "create disorder and confusion," probably related to Middle Dutch rommelen "to rumble," Middle High German rummeln, Old Norse rymja "to shout, roar," all of imitative origin. Slang sense of "engage in a gang-fight" is by 1959. Related: Rumbled; rumbling.
1580s, from Late Latin ventriloquus, from Latin venter (genitive ventris) "belly" (see ventral) + loqui "to speak" (from PIE root *tolkw- "to speak"). Related: Ventriloquial; ventriloquize.
Patterned on Greek engastrimythos, literally "speaking in the belly," which was not originally an entertainer's trick but rather a rumbling sort of internal speech, regarded as a sign of spiritual inspiration or (more usually) demonic possession. Reference to the modern activity so called seems to have begun early 18c., and by 1797 it was being noted that this was a curiously inappropriate word to describe throwing the voice.
Old English grimm "fierce, cruel, savage; severe, dire, painful," from Proto-Germanic *grimma- (source also of Old Saxon, Old Frisian, Old High German, German grimm "grim, angry, fierce," Old Norse grimmr "stern, horrible, dire," Swedish grym "fierce, furious"), from PIE *ghremno- "angry," which is perhaps imitative of the sound of rumbling thunder (compare Greek khremizein "to neigh," Old Church Slavonic vuzgrimeti "to thunder," Russian gremet' "thunder").
A weaker word now than it once was; sense of "dreary, gloomy" first recorded late 12c. It also had a verb form in Old English, grimman (class III strong verb; past tense gramm, past participle grummen), and a noun, grima "goblin, specter," perhaps also a proper name or attribute-name of a god, hence its appearance as an element in place names.
Grim reaper as a figurative phrase for "death" is attested by 1847 (the association of grim and death goes back at least to 17c.). A Middle English expression for "have recourse to harsh measures" was to wend the grim tooth (early 13c.).