Washingtonian rhymes with:
bostonian, estonian, houstonian, newtonian, plutonian, amazonian, andonian, apollonian, babylonian, bostonian, caledonian, devonian, draconian, estonian, gorgonian, houstonian, jacksonian, jeffersonian, melkonian, newtonian, oregonian, patagonian, plutonian, simonian, smithsonian, usoniam
Washingtonian sounds like:
washington, wiggington, wigington