Fully serious or committed

पूरी तरह गंभीर या प्रतिबद्ध

English Usage: He was in deadly earnest when he said he would quit his job.

Hindi Usage: जब उसने कहा कि वह अपनी नौकरी छोड़ देगा, तो वह पूरी तरह गंभीर था।