malady
a sickness or illness; bad health
malefactor
a person who does the wrong thing; an evil person
malevolent
Wishing evil or bad to others; mean
malefeasance
Bad conduct or wrongdoing by a public official
malfunction
to function imperfectly or badly; fail to operate normally
malice
a desire to do something bad to someone else; doing something that is wrong on purpose
malignant
Very bad or harmful; likely to cause death
malnutrition
a poor diet; bad eating habits that result in poor health
malodorous
...
malpractice
an instance of bad conduct or treatment from a doctor or other professional