The Oxford Thesaurus An A-Z Dictionary of Synonyms - sneakingadj.

1) persistent, lingering, lurking, nagging, worrying, worrisome, niggling, intuitive, deep-rooted, deep-seated, Slang gut: She had a sneaking suspicion that Stephen was a police informer. 2) innate, intuitive, inherent, private, secret, suppressed, hidden, unexpressed, undeclared, unvoiced, unavowed, unconfessed, unrevealed, unadmitted, undivulged, undisclosed, covert: I have a sneaking sympathy with the underdog.