surreptitiously

/ˌsɜrəpˈtɪʃəsli/
adverb
  1. In a secret or stealthy manner; so as not to be noticed.
    • She surreptitiously slipped a note into his backpack.
    • The spy surreptitiously photographed the documents.
    • He surreptitiously checked his watch during the long speech.
Antonyms
What does "surreptitiously" mean? | whatsthatwordmean | whatsthatwordmean