The word “sundara” is common in Tamil literature, especially in bhakthi poetry. As far as I can see, the first occurrence of it is found in the epic Cilappatikaram, as “sundara cunnam” [rendered properly as “cuntara-c cuṇṇam”] to refer to 'colorful fragrant powder' ('சுந்தரச் சுண்ணம்’).

Śiva in Madurai temple is known as “ālāla cuntarar” (or, "Alaala Sundarar”)

Regards,

Rajam