[adjective] [not gradable] - (of feelings such as respect and admiration) unwilling or secret, usually because felt for a person whose basic character or moral principles you do not like or trust, or (of a belief, esp. an unpleasant one) not certain but probably trueI don't like the woman and I certainly don't like what she stands for, but I do have a sneaking admiration for her.I've got a sneaking feeling/suspicion that we're going the wrong way.
SNEAKING
Meaning of SNEAKING in English
Cambridge English vocab. Кембриджский английский словарь. 2012