A very brief account; esp, a quick biography
[1852+; so brief, that is, as to be written on a thumbnail]
From the thumbnail sketch to the many variations of a conceptual scheme, one eliminating the other, many decisions are arrived at.
Well, give me in a thumbnail sketch, something about Mr. Jitkoff's background.
Cummings' life is scarcely even a sketch; at most it is a thumbnail sketch.