Why is the ninth month called September?
mid-14c., from Old French hiene, from Latin hyaena, from Greek hyaina "swine" (fem.), from hys "pig" + fem. suffix -aina. So called for its bristles. Applied to cruel, treacherous, and greedy persons since at least 1670s. Adjectival forms that have been attempted in English include hyenaish, hyenaesque, hyenic, hyenine.