asperity

The quality of having a rough or uneven surface; roughness, unevenness; (countable, chiefly in the plural) a protruding or rough area or point on a surface; a protrusion.

Oyle of ſwete Almondes and of ſiſami taketh away the aſperitie and rougheneſſe of the throte.

The iuyce of Mynte mengled with honied water, cureth the payne of the eares being dropped therein, and taketh away the aſperitie, and roughneſſe of the tongue, whan it is rubbed or waſſhed therewith.

The quality of having a rough or uneven surface; roughness, unevenness; (countable, chiefly in the plural) a protruding or rough area or point on a surface; a protrusion.

We inferred that the locking of asperities did cause higher stresses associated with earthquake cycle itself to occur in areas adjacent to asperities, both updip and downdip from them, and that such stressing has been much less pronounced in the areas adjacent to non-asperities.

Since rapid permanent plate shortening is not observed in subduction zones, there must be either strain release over a large region or strain accumulation over a small region over earthquake cycles. […] The most likely mechanism for the latter is the accumulation of elastic strain around isolated locked asperities of the fault, which requires significant aseismic fault slip between asperities.

The quality of being difficult or unpleasant to experience; (countable) a thing that is harsh and difficult to endure; a difficulty, a hardship.

the asperity of Maine’s winter

If the faith were in our daies as feruēt [fervent] as it hath bene ere this, in tyme before passed, litle counſayle and litle comfort would ſuffice. We ſhould not muche nede with wordes and reaſoning, to extenuate and minyſh the vygour and aſperitie of the paynes, but the greatter ⁊ the more bitter that the paſſion wer, the more ready was of olde tyme the feruor of faith to ſuffer it.

The quality of being harsh or severe in the way one behaves or speaks toward another person; (countable, chiefly in the plural) a deeply hostile or resentful feeling; an animosity, a hatred.

But leaſt he ſhoulde offend the Iewes with the aſperitie of the word, if hee had ſaid that the lawe was dead, hee vſed a digreſſion, or deflection, ſaying, we are dead to the law.

[H]e [God] vvill reprove them ſharply for their uncharitable bitterneſs one againſt another, and menace them even vvith deſtruction, if they leave not off their animoſities and aſperities of mind about toys and trifles, and hold faſt to the Royal Lavv of Love […]

Of sound: gratingness, harshness.

[T]he importunate, harſh and diſharmonious Coaxations of Frogs, (ſo called in the Greek from that very ungratefull noiſe, […] from the ſhrilneſs and aſperity of the noiſe they make) […]

[John] Miltonm therefore ſeems to have ſomevvhat miſtaken the nature of our language, of vvhich the chief defect is ruggedneſs and aſperity, and has left our harſh cadences yet harſher.