a coarse prickly European weed with spikes of blue flowers; naturalized in United States
any of numerous plants of the family Compositae and especially of the genera Carduus and Cirsium and Onopordum having prickly-edged leaves
of the color intermediate between green and violet; having a color similar to that of a clear unclouded sky
used to signify the Union forces in the American Civil War (who wore blue uniforms)
blue color or pigment; resembling the color of the clear sky in the daytime
any organization or party whose uniforms or badges are blue
filled with melancholy and despondency
the sky as viewed during daylight
