adj. 1. Very good; excellent; -- an informal term meaning about the same as groovy, sense 1. [ informal, 1960's ] Syn. -- bang-up, bully, cool, corking, cracking, dandy, great, groovy, keen, neat, not bad(predicate), peachy, slap-up, swell, smashing. [ WordNet 1.5 ]
2. Stylish; attractive; -- of clothing; as, a nifty outfit. [ PJC ]