the head of a school or organization

most important

सबसे महत्वपूर्ण

English Usage: The principal cause of the issue was not identified.

Hindi Usage: समस्या का प्रमुख कारण नहीं पहचाना गया।

a mountain or hill that erupts with lava, rock fragments, and gas

an active volcano

एक सक्रिय ज्वालामुखी

English Usage: They traveled to see the active volcano in Hawaii.

Hindi Usage: वे हवाई में सक्रिय ज्वालामुखी देखने गए।