the first in rank or importance

the first of its kind

प्रथम

English Usage: This invention is considered primus in the field of technology.

Hindi Usage: यह अविष्कार प्रौद्योगिकी के क्षेत्र में प्रथम माना जाता है।

to act as the first or leader

नेतृत्व करना

English Usage: He was primus in organizing the event.

Hindi Usage: वह इवेंट का नेतृत्व करने में प्रमुख था।