Saturnine

Saturnine is an adjective.

Meaning: gloomy, dark, sullen

Secondary meaning: of or relating to lead, symptomatic of lead poisoning.

Helpful hints: 
The saturnine planet, Saturn, must really feel gloomy. I certainly would with all those rings around my eyes. It appears quite dark which I guess is why everyone thought it was made of lead. 

Fun factoids: 

Sixth planet from the sun. 

Second largest in the solar system.

Saturn has nine rings. 

It has 62 moons that orbit.