Malignant (adjective)
Harmful, malevolent, injurious.
“malignant temper;”
“malignant revenge;”
“malignant infection”
Malignant (adjective)
Tending to produce death; threatening a fatal issue.
“malignant diphtheria”
“a malignant tumor”
Malignant (noun)
A deviant; a person who is hostile or destructive to society.
Malignant (noun)
A person who fought for Charles I in the English Civil War.
Benign (adjective)
Kind; gentle; mild.
Benign (adjective)
(of a climate or environment) mild and favorable
Benign (adjective)
Not harmful to the environment.
“an ozone-benign refrigerant”
Benign (adjective)
Not posing any serious threat to health; not particularly aggressive or recurrent.
Benign (adjective)
gentle and kind
“his benign but firm manner”
Benign (adjective)
(of a climate or environment) mild and favourable
“the climate becomes more benign as we move nearer to the Black Sea”
Benign (adjective)
not harmful to the environment
“an ozone-benign refrigerant”
“the cycle as a benign form of transport”
Benign (adjective)
(of a disease) not harmful in effect
“a benign condition”
Benign (adjective)
(of a tumour) not malignant
“benign growths”