surreptitious
Cross references: 1. secret sur.rep.ti.tious \.s*r-*p-'tish-*s, .s*-r*p-, s*-.rep-\ aj [ME, fr. L surrepticius, fr. surreptus, pp. of surripere to s]natch secretly, fr. sub- + rapere to seize - more at RAPID 1: done, made, or acquired by stealth : CLANDESTINE 2: acting or doing something clandestinely : STEALTHY - sur.rep.ti.tious.ly av