You aren't likely to find adumbrate in children's stories or on the sports pages. That's not because this shady word is somehow off-color, but rather because it tends to show up most often in academic or political writing. In fact, some usage commentators find it too hard for "ordinary" use (although they are hard-pressed to define "ordinary"). Art and literary critics have long found it useful, and it's a definite candidate for those oft-published "lists of words you should know" (especially for vocabulary tests). You might remember adumbrate better if you know that it developed from the Latin verb adumbrare, which in turn comes from umbra, the Latin word for "shadow." To adumbrate, then, is to offer a shadowy view of something.
the strife in Bloody Kansas in the 1850s adumbrated the civil war that would follow
Recent Examples on the WebIn between, works by contemporaries complicate superficial ideas about his meteoric genius, and small, delicate drawings teem with an abundance of ideas — paintings never made, thoughts adumbrated then abandoned. Philip Kennicott, Washington Post, 18 Oct. 2019 Nothing in America’s tepid 19th-century contributions to European classical music adumbrated it; nor did the homely and sometimes hokey popular songs of Stephen Foster. Heather Mac Donald, National Review, 22 Aug. 2019 The helicopter crash, on the other hand, is a narrative dead end, merely adumbrating the portrait that Mr. Davenport will draw of Mr. Bezos as unflappable. Randall Stross, WSJ, 15 Apr. 2018
Word History
Etymology
borrowed from Latin adumbrātus, past participle of adumbrāre "to shade, represent by means of light and shade, sketch, outline," from ad-ad- + -umbrāre, verbal derivative of umbra "shadow" — more at umbrage