(Orexin comes from the Greek word for appetite, "orexis ''.).    From Wordnik.com.  [Boston.com Most Popular] Reference

Rather it is hoped that the haecceity of this enchiridion of arcane and recondite sesquipedalian items will appeal to the oniomania of an eximious Gemeinschaft whose legerity and sophrosyne, whose Sprachgefühl and orexis will find more than fugacious fulfillment among its felicific pages. ".    From Wordnik.com.  [languagehat.com] Reference