1. lacking qualities that excite, stimulate, or interest; dull 2. lacking flavor or zest; not tasty

The last one from Doctor Glas: “Our love of beauty knows no other source. All art, all poetry, all music has drunk at it. The most insipid modern historical painting, every bit as much as Raphael’s madonnas and Steinlen’s little Parisian working girls … springs from this origin, albeit often by the longest and most circuitous of routes.”