A very low rate of frequency, often used in the context of radio waves or audio signals.

अत्‍यंत कम आवृत्ति

English Usage: The communication system uses extremely low frequency for long-distance transmissions.

Hindi Usage: संचार प्रणाली दीर्घ दूरी प्रसारण के लिए अत्‍यंत कम आवृत्ति का उपयोग करती है।