mor·bid 
(môrbĭd)
(môrbĭd)adj.
1. Given to or characterized by unwholesome thoughts or feelings, especially of death or disease: read the account of the murder with a morbid interest.
2.
a. Of, relating to, or caused by disease; pathological or diseased: morbid changes in tissues.
b. Psychologically unhealthy or unwholesome: a morbid fear of heights.
[Latin morbidus, diseased, from morbus, disease; see mer- in the Appendix of Indo-European roots.]
morbid·ly adv.
morbid·ness n.