கீழ்நீர், மேல்நீர்கள் two sources of water, viz., underground water as that in springs, wells and tanks, and surface water as in lakes and rivers இருபுனல் இரு + புனல்
double funnel
Tamil Wiktionary
இருபுனல் — பெயர்ச்சொல் (Noun)
கீழ்நீர், மேல்நீர்கள்
two sources of water, viz., underground water as that in springs, wells and tanks, and surface water as in lakes and rivers
+. Two sources of water, viz., underground water as that in springs, wells and tanks, and surface water as in lakes and rivers; கீழ்நீர் மேல்நீர்கள். (குறள், 737.)