உபநாயகன்

சோரநாயகன். Paramour, illicit partner of a married woman;

Tamil Lexicon

s. (உப) illicit partner, of a married woman, சோர புருஷன். (also உபபதி).

J.P. Fabricius Dictionary

upa-nāyakaṉ
n. upa+.
Paramour, illicit partner of a married woman;
சோரநாயகன்.

DSAL