1) Clean 2) Groom 3) Make more alert 4) Make more stylish 5) Make more trim 6) Make spruce 7) Spruce up 8) Tidy 9) Trim Found on https://www.crosswordclues.com/clue/smarten
Smart'en transitive verb To make smart or spruce; -- usually with up . [ Colloq.] « She had to go and smarten herself up somewhat.» W. Black. Found on http://www.encyclo.co.uk/webster/S/126