unobserved
From LSJ
νόσημα γὰρ αἴσχιστον εἶναί φημι συνθέτους λόγους → for I consider false words to be the foulest sickness
English > Greek (Woodhouse)
adjective
do a thing unobserved: P. and V. λανθάνειν ποιῶν τι, V. λήθειν ποιῶν τι.
unobserved by: use Ar. and V. λάθρα (gen.), P. κρύφα (gen.).