"gloomy, morose, sluggish, grave," mid-15c., literally "born under the influence of the planet Saturn," from Middle English Saturne (see Saturn) + -ine (1). Medieval physiology believed these characteristics to be caused by the astrological influence of the planet Saturn, which was the most remote from the Sun (in the limited knowledge of the times) and thus coldest and slowest in its revolution.
saturnine sat·ur·nine (sāt'ər-nīn')
Melancholy or sullen.
Produced by absorption of lead.