Having a harmful effect, especially in a gradual or subtle way.

हानिकारक प्रभाव डालना

English Usage: The tumor was found to be malignant.

Hindi Usage: पता चला कि कैंसर ट्यूमर हानिकारक है।

Very virulent or infectious.

Malevolent; evil in nature.

दुष्ट स्वभाव का

English Usage: He had a malignant grin that made everyone uneasy.

Hindi Usage: उसके पास एक दुष्ट हंसी थी जो सभी को असहज कर देती थी।