Ghastly or sinister.
Rigid and unrelenting.
Disgusting; gross.
Dismal and gloomy, cold and forbidding.
To make grim; to give a stern or forbidding aspect to.
Grisly or gruesome.
Of, or relating to disease.
Suggesting the horror of death; macabre or ghoulish.
Taking an interest in, or fixating on, unhealthy or unwholesome subjects such as death, decay, disease.