The term 'COOL! OLD-STYLE' can be summarized by three crossword solutions: NEATO (5 letters), HEP (3 letters), and NEAT (4 letters). NEATO is an informal slang term meaning 'very impressive or attractive', while HEP is an adjective meaning 'in the know' or 'aware of the latest trends'. Finally, NEAT is an adjective meaning 'tidy and well-organized'. All three words describe something that is cool and old-style, suggesting a combination of classic style with modern trends.