Mo'n: as in "more than"
"Aint I drove fer T.P. mo'n a hund'ed times?" (The Sound and the Fury, p. 318).

Mont: as in "month"
"'Mr. Jason,' he says. 'Please, suh. I'll fix dem tires ev'y day fer a mont'" (The Sound and the Fury, p. 255).

Moribund: approaching death or on the verge of becoming obsolete
"The gown fell gauntly from her shoulders, across her fallen breasts, then tightened upon her paunch and fell again, ballooning a little above the nether garments which she would remove layer by layer as the spring accomplished and the warm days, in color regal and moribund" (The Sound and the Fury, p. 265).

Mother hubbard: long, loose dress worn by rural women
"She now wore a faded mother hubbard and a sun bonnet, and she carried a cedar bucket" (Light in August, p. 151).

Mouf: as in mouth
"Hush yo mouf" (The Sound and the Fury, p. 254).

Mought: as in "might" or "ought"
"The driver spits. 'We mought,' he says" (Light in August, p. 28).

Natural: uncultivated, or in this case, simple-minded
"…Benjys the natural isn't he…" (The Sound and the Fury, p. 160).

Negative: to negate, nullify
"I gave Anse Dewey Dell to negative Jewel" (As I Lay Dying, p. 176).

Nekkid: as in "naked", bare, unsheathed
"'…Pappy Thompson's daughter's boy, that was six foot tall and had a razor nekkid in his hand'" (Light in August, p. 323).

Niggard: stingy, miserly
"Flowing around you, not brooding and nursing every niggard stone" (The Sound and the Fury, p. 113).

Nigh/Nigher: near/nearer
"He is carrying a fish nigh long as he is" (As I Lay Dying, p. 30).

"'It won't float like a saw,' Jewel says. 'It'll float nigher to a saw than a hammer will,' Vernon says" (As I Lay Dying, p. 161).

"By the second day she was well nigh desperate" (Light in August, p. 123).

Nimbus: a classical radiance said to surround a classical deity when on earth
"…he appears to be enclosed in a thin nimbus of fire" (As I Lay Dying, p. 222).

Noblesse oblige: the concept that those with high rank should act in a responsible manner
"…I at least revealed a blundering sense of noblesse oblige by getting myself born below Mason and Dixon…" (The Sound and the Fury, p. 91).

Nome: as in "no ma'am"
"'Nome.' Versh said" (The Sound and the Fury, p. 7).

Non fui. Sum. Fui. Non sum.: Latin: "I wasn't. I am. I was. I'm not."
"Non fui. Sum. Fui. Non sum" (The Sound and the Fury, p. 174).

Off: euphemism for poor, or unfortunate; as a farm term, "off" refers to the horse or ox on the far right side of the driver.
"...Peabody's team come up, lathered, with the broke harness dragging and the neck-yoke betwixt the off critter's legs..." (As I Lay Dying, p. 68).

Otherlike: as in "otherwise"
"I have done things but neither better nor worse than them that pretend otherlike…" (As I Lay Dying, p. 38).

Ourn: as in "ours"
"'She'll want to go in ourn,' Pa says" (As I Lay Dying, p. 18).

Outen: as in "out in" or "out of"
"Washed clean outen the ground it will be" (As I Lay Dying, p. 90).

"You can whup the blood outen me. But that's all I know" (Light in August, p. 293).