Saturday · saturnine
Saturn's day; gloomy
Today this word meansThe last day of the week. And a heavy, gloomy temperament.
The day of Saturnus, the Roman name of Cronus — a rare case of a weekday keeping its Roman god's name intact.
From the observation that Saturn moves slowest, astrology tied the planet to a heavy, melancholy disposition. That is where saturnine comes from.