insidiosus

īnsidiōsus adj.with comp.

insidiae, cunning, deceitful, treacherous, dangerous : leno, H.: quis insidiosior (est)?: sermo.

insidiosus
insĭdĭōsus, a, um, adj. [insidiae], cunning, artful, deceitful, dangerous, insidious (class.). I O...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.