Immediately, without any hesitation or delay

बिना किसी हिचकिचाहट के, तुरंत

English Usage: She would leave her job at the drop of a hat if she got a better offer.

Hindi Usage: बेहतर प्रस्ताव मिलते ही वो तुरंत अपनी नौकरी छोड़ देगी।