Those belonging to lower castes address those in upper castes as 'Thampuran' (In the case of women it was Thampuratty). Now 'Sir' and 'Madam' are being used as Malayalam words here, since most are literate and school educated. tmsankaran...
as evidenced in his ‘abhithistavam’,“Kvachana rangamukyE vibhO! paraspara-hithaishiNAm parisarEshu mAm varthaya”, (O Lord!, let me reside in Srirangam at the feet of the great ones who are mutual well-wishers)2.