Uncleanly comes from un- ('not') + cleanly, from Old English clænlic ('clean, pure'), from clæne ('clean') + -lic ('-ly'). Carries both the adjectival sense 'habitually dirty' and the adverbial 'in an unclean manner'. The historical chain includes Old English un- and Old English clænlic. The quoted older senses, "not", "clean, pure", "clean", "-ly", and "habitually dirty", supply the semantic anchors for uncleanly. The formation is best read as suffixal, compound, and borrowed: the word uncleanly carries its older form-history into a compact English lexical shape. In present English it is used as a adj, "habitually dirty; in an unclean manner". English derivatives include uncleanliness; related English forms include unclean, clean, cleanly, and cleanliness. The result is a adj and adv whose etymology preserves both the older form and the later English specialization.