say it: sur-uhp-TISH-uhs
surreptitious is an adjective meaning "marked by quiet and caution and secrecy; taking pains to avoid being observed". It carries 2 recorded senses.
conducted with or marked by hidden aims or methods
“clandestine intelligence operations”
“cloak-and-dagger activities behind enemy lines”
“hole-and-corner intrigue”
“secret missions”
“a secret agent”
“secret sales of arms”
“surreptitious mobilization of troops”
“an undercover investigation”
“underground resistance”
Definitions, synonyms and semantic relations for surreptitious 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.