cry wolf

Old English wulf, from Proto-Germanic *wulfaz (cf. Old Saxon wulf, Old Norse ulfr, Old Frisian, Dutch, Old High German, German wolf, Gothic wulfs), from PIE *wlqwos/*lukwos, from root *wlp-/*lup- (cf. Sanskrit vrkas, Avestan vehrka-; Albanian ulk; Old Church Slavonic vluku; Russian volcica; Lithuanian vilkas "wolf;" Old Persian Varkana- "Hyrcania," district southeast of the Caspian Sea, literally "wolf-land;" probably also Greek lykos, Latin lupus).

Wolves as a symbol of lust are ancient, e.g. Roman slang lupa "whore," literally "she-wolf" (preserved in Spanish loba, Italian lupa, French louve). The equation of "wolf" and "prostitute, sexually voracious female" persisted into 12c., but by Elizabethan times wolves had become primarily symbolic of male lust. The specific use of wolf for "sexually aggressive male" first recorded 1847; wolf-whistle first attested 1952. The image of a wolf in sheep's skin is attested from c.1400. See here for a discussion of "wolf" in Indo-European history.