say it: sur-uhp-TISH-uh-slee
surreptitiously is an adverb meaning "in a surreptitious manner". It carries one recorded sense.
in a surreptitious manner
“he was watching her surreptitiously as she waited in the hotel lobby”
Definitions, synonyms and semantic relations for surreptitiously come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.