Overshadowed by "umbrage"; or, you learn something old every day

My student wanted to know what umbrage meant in a poem by Wordsworth, and although I know what umbrage means in the phrase to take umbrage, I took umbrage over the use of the word in these lines describing the earth beneath a grove of yew trees:

                                              a pillared shade,
Upon whose grassless floor of red-brown hue,
By sheddings from the pining umbrage tinged
Perennially...

"It looks like umbrage is being used as a color word," I said, "but that doesn't make sense."

"You could Google it," my student said, and so we did, and you'll never guess what we found: umbrage survives in common use today only in phrases like to take umbrage, but in the past it carried a whole host of usages as a term relating to shadow. The OED lists dozens of citations for umbrage meaning shadow or shade, alongside figurative uses meaning a feeling of suspicion or doubt or even a suspicion, hint, inkling, or slight idea. I had no inkling that an umbrage could be an inkling.

I was even more surprised to find that umbrage was once used as a verb with meanings like to shade or shadow, or to overshadow, or even to disguise, as in this example from the OED: 

1675   R. Burthogge Cavsa Dei 312   If she mentioned others, it was by way of caution, only to secure her self, and Umbrage what she said that it might down the better.

Apparently, just a spoonful of umbrage makes the medicine go down. But the woman above may have found her match in a young gallant described under the meaning to give a pretext for:

1689   E. Hickeringill Speech Without-doors 35   Like that young Gallant, studying what he should see in her [sc. an old woman] to Vmbrage the fondness of his Embraces.

So umbrage leads us into the shadows, where women shade their meanings to make them more palatable while young men invent pretexts to embrace older women. That's pretty far from today's meaning, but not far from Wordsworth's usage to describe the shade under a grove of yew trees--the kind of umbrageous place that could provide cover for all kinds of shady behavior.