Various Greek formations containing an element (-)δευκ- are to be analysed as containing reflexes of a PIE root *deuk- ‛appear‘. These forms are to be separated, semantically and etymologically, from the root which surfaces in the second member of the adverb ἐλδπκέσο ‛continuously, carefully‘. For the latter, a connection with a homo-nymous *deuk- ‛stitch‘ (known only from Iranian) is suggested.