- (US) IPA: /ˌsɜɹ.əpˈtɪʃ.əs/
From Latin surrepticius (“stolen, furtive, clandestine”), from surreptus, past participle of surripere ("seize secretly, steal, pilfer"), from sub- ("under") + rapere ("to snatch").
surreptitious (comparative more surreptitious, superlative most surreptitious)
- stealthy, furtive, well hidden, covert (especially movements)
Derived terms 
stealthy, furtive, well hidden, covert