obreptitious
adjective
ob·rep·ti·tious
¦äˌbrep¦tishəs
: marked by obreption : done or obtained by trickery or by concealing the truth
obreptitiously adverb
Word History
Etymology
Late Latin obrepticius, obreptitius, from Latin obreptus (past participle of obrepere) + -icius, -itius -itious