The Collaborative International Dictionary
Gnathonical
Gnathonic \Gna*thon"ic\, Gnathonical \Gna*thon"ic*al\, a. [L. Gnatho, name of a parasite in the ``Eunuchus'' of Terence, Gr. ?; hence, a parasite in general.] Flattering; deceitful. [Obs.]
Wiktionary
gnathonical
a. (alternative form of gnathonic English)