If nothing else, the architect has swelled the number of adjectives used in discussing Chicago design.A whole roster of words have entered the lexicon of the city's core to describe his latest concoctions. The German-born designer has pulled out the full repertoire of architectural stops. Swirls, slopes, swerves, scallops - not to mention undulations, truncations, and stops and starts of all the above - characterize his structures.For much of a decade, Jahn has gone to all lengths to avoid the right-angled box, from the low, round, checkerboard Argonne National Laboratory to the erratic, jutting red and blue missile planned for a South African commercial building.