From Longman Dictionary of Contemporary Englishsurreptitioussur‧rep‧ti‧tious /ˌsʌrəpˈtɪʃəs◂ $ ˌsɜː-/ adjective SECRETdone secretly or quickly because you do not want other people to notice Rory tried to sneak a surreptitious glance at Adam’s wristwatch. —surreptitiously adverb —surreptitiousness noun [uncountable]
Examples from the Corpus
surreptitious• Fortunately, his surreptitious action also turned out to be illegal.• Women in nightdresses peeping out of roadside houses lent a surreptitious air to the first few miles.• The back avoids eye contact and confrontation, but it may invite the surreptitious gaze.• Then a little light came through the uncovered spyhole, a flickering, surreptitious light.• The result was that we all kept making surreptitious trips to the staff room to refill our plastic beakers.• Solitary, masochistic, surreptitious vice, that's all he understands. 