An Etymological Dictionary of the German Language/Annotated/schmuggeln
schmuggeln, verb, ‘to smuggle,’ Modern High German only, formed from the equivalent Low German smuggeln; compare Dutch smokkeln, English to smuggle (borrowed from the same source?). The originally word is connected with the root smug, ‘to wind,’ to which the secondary sense of ‘secrecy’ may belong; compare Dutch smuigen, ‘to enjoy oneself secretly.’