1. To foreshadow.
2. To give a rough outline or to disclose partially.
3. To overshadow or obscure.
From Latin umbra (shade, shadow), which also gave us the words umbrella, umbrage, and somber. Earliest documented use: 1599.
“Mr Cameron should adumbrate painful decisions; he should sketch out the principles that will inform them; but he should not be drawn into spelling out what exactly they will be.”
Walter Bagehot; Coming Clean; The Economist (London, UK); Mar 26, 2009.
“To create her three-dimensional composition, Robin Osler variedly manipulated floor and ceiling planes so as to adumbrate virtual spaces.”
Monica Geran; Shadow Play; Interior Design (New York); Apr 2000.
Explore “adumbrate” in the Visual Thesaurus.