அளபெடை - விளாங்காய் அன்று.
An earlier thread in SV on this topic:
வெண்பாவில் விளாங்காய்ச் சீர் -
https://groups.google.com/g/santhavasantham/c/uGfPcmFo6bY
அளபெடை - many people may not know how to pronounce when it occurs in a verse.
The vowel sound is elongated for a longer duration - for sound effect or for meter conformance needs.
For an example: See the section - "Notes on Pronunciation - Tamil poetry conventions - for some words in this verse"
that follows the Sivapuranam verse in the thevaram class page:
V. Subramanian