Old English greot "sand, dust, earth, gravel," from Proto-Germanic *greutan "tiny particles of crushed rock" (cf. Old Saxon griot, Old Frisian gret, Old Norse grjot "rock, stone," German Grieß "grit, sand"), from PIE *ghreu- "rub, grind" (cf. Lithuanian grudas "corn, kernel," Old Church Slavonic gruda "clod"). Sense of "pluck, spirit" first recorded American English, 1808.
"make a grating sound," 1762, probably from grit (n.). Related: Gritted; gritting.
To eat (1930s+ Black)
[food senses at least partially fr hominy grits, although grit was British military slang for ''food'' in the 1930s; Southern dialect sense probably ironically fr Civil War use of the expression true Yankee grit by Northern soldiers and writers]