undercover

There's a word that i can almost remember. it's driving me crazy. it means undercover or masked i think. i remember hearing it as the name of a perfume a long time ago (like early 90s) and i thought it was a great word. i keep wanting to say serendipity so i think it might start with an s. why this is bothering me so much i don't know. i've tried every work i can think of in the thesauras and i just can't find it. i'll know it when i see it, but it's nowhere.

Main Entry: ob·scure
Pronunciation:äb-'skyur, &b-
Function:adjective
Etymology:Middle English, from Middle French obscur, from Latin obscurus

1 a : DARK, DIM b : shrouded in or hidden by darkness c : not clearly seen or easily distinguished : FAINT
2 : not readily understood or clearly expressed; also : MYSTERIOUS
3 : relatively unknown: as a : REMOTE, SECLUDED b : not prominent or famous
synonyms OBSCURE, DARK, VAGUE, ENIGMATIC, CRYPTIC, AMBIGUOUS, EQUIVOCAL mean not clearly understandable. OBSCURE implies a hiding or veiling of meaning through some inadequacy of expression or withholding of full knowledge (obscure poems). DARK implies an imperfect or clouded revelation often with ominous or sinister suggestion (muttered dark hints of revenge). VAGUE implies a lack of clear formulation due to inadequate conception or consideration (a vague sense of obligation). ENIGMATIC stresses a puzzling, mystifying quality (enigmatic occult writings). CRYPTIC implies a purposely concealed meaning (cryptic hints of hidden treasure). AMBIGUOUS applies to language capable of more than one interpretation (an ambiguous directive). EQUIVOCAL applies to language left open to differing interpretations with the intention of deceiving or evading (moral precepts with equivocal phrasing).