One of the flower names, used occasionally in Britain (where it's pronounced DAY-lee-a). It seems to have recovered from what was perceived as a slightly affected la-di-dah air -- it climbed into the top 400 over the past three years. The flower was named in honor of the pioneering Swedish botanist Anders Dahl, which means dale.
In the Victorian language of flowers, Dahlia denotes elegance and dignity.
In P.G. Wodehouse's Jeeves stories, Dahlia is Bertie Wooster's more sympathetic aunt, described as being constructed along the lines of Mae West. Reporter Dahlia Lithwick covers legal matters for the online magazine Slate.