Is it ensure, insure, or assure?
"thin, meager," 1630s; any modern use traces to Milton ("Lycidas," 124), who may have invented it out of dialectal scranny (see scrawny). Or it might be from a Scandinavian source akin to Norwegian skran "rubbish." Cf. English dialectal and Scottish skran "scraps, broken victuals; refuse," in military slang "food."