Both Uses

devise
in
The Reptile Room
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Although it was frightening to be trapped in his inner sanctum—a phrase which here means "filthy room in which evil plans are devised"—it turned out to be quite useful, because they were able to read up on nuptial law and work their way out of their predicament.†
p. 116.4

devised = came up with (invented or created)
You and I know, of course, that Mr. Poe was panicking over Sunny and the Incredibly Deadly Viper, but all Violet knew was that whatever ruse her siblings had devised was still working.†
p. 141.3 *

Definitions:

(1) (devise as in: devise a plan)
to come up with a way of doing something -- typically a creative idea or plan
(2) (meaning too rare to warrant focus)
In law, devise can also reference a gift given in a will (or the act of bequeathing such a gift).