late Old English sceorf, from Proto-Germanic *skurf- (source also of Danish skurv, Middle Dutch scorf, Dutch schurft, Old High German scorf, German Schorf "scurf"), probably related to Old English sceorfan "to gnaw," scearfian "to cut into shreds" (from PIE *skerp-, from root *sker- (1) "to cut").
adjective suffix, "full of or characterized by," from Old English -ig, from Proto-Germanic *-iga- (source also of Dutch, Danish, German -ig, Gothic -egs), from PIE -(i)ko-, adjectival suffix, cognate with elements in Greek -ikos, Latin -icus (see -ic). Originally added to nouns in Old English; used from 13c. with verbs, and by 15c. even with other adjectives (for example crispy).
1560s, noun use of adjective scurvy "covered with scabs, diseased, scorbutic" (early 15c.), variant of scurfy. It took on the narrower meaning of Dutch scheurbuik, French scorbut "scurvy," in reference to the disease characterized by swollen and bleeding gums, prostration, etc., perhaps from Old Norse skyrbjugr, which is perhaps literally "a swelling (bjugr) from drinking sour milk (skyr) on long sea voyages;" but OED has alternative etymology of Middle Dutch or Middle Low German origin, as "disease that lacerates the belly," from schoren "to lacerate" + Middle Low German buk, Dutch buik "belly."