The paper aims to reconsider the etymology of South-Slavic folklore term neveda ‘maleficent supernatural being, misfortune’, hitherto interpreted as *ne-věda, a compound consisting of the negative prefix *ne- and the verbal stem *věd- ‘to see > to know’. However, the late attestation of the word (20th century) and instances of the initial cluster dn- reduced to n- (Dnemrak 1839, today Nemrak) suggest another Common Slavic protoform underlying, *dьne-věda ‘apparition in daylight’, a variant of Balto-Slavic *āvi-vaidas as reflected in Lithuanian óvaidas ‘mischevious boy, scamp’, Serbian dial. àved ‘ghost, apparition, scare-crow’, Ukrainian dial. jávyda ‘devil’, Russian dial. jávid’ ‘a snake found in the tundra’, where *āvi- denotes what is really seen as opposed to vi- sions or dreams and *vaida- means ‘apparition’; a similar semantic nar- rowing of the Proto Indo European root *oid- is observed in Old Indian véda- ‘knowledge obtained through divine revelation’.