Old English wisnian, weosnian "to wither, dry up, waste away," from Proto-Germanic *wisnon (source also of Old Norse visna "to wither," Old High German wesanen "to dry up, shrivel, wither;" German verwesen "to decay, rot"). Related: Wizened.
late 14c., "to roast or dry" (peas, beans, corn, etc.), a word of uncertain origin. Klein and OED reject derivations from Old North French perchier (Old French percer) "to pierce" and Latin persiccare "to dry thoroughly." Century Dictionary, The Middle English Compendium, and Barnhart suggest it could be from Middle English perchen, a variant of perishen "to perish" (see perish). Klein "tentatively" suggests a back-formation from parchment. A surname Parchecorn is attested from mid-14c. Meaning "to dry with excessive heat, expose to the strong action of fire but without burning" is from mid-15c. Related: Parched; parching.
From late 14c. as "severe, rigid;" 1590s as "unadorned, simple in style, without luxuries;" 1660s as "grave, sober." Classical literal sense "sour, harsh" (1540s) is rare in English. Related: Austerely; austereness.