Definitions
a region of complete shadow resulting from total obstruction of light
Word origin
Borrowed from Latin umbra (“shadow”). Doublet of umber.
Used in a sentence
“In order to set up such an algorithm, we need the notion of multiplicative inverse of an umbra. Two umbrae are said to be multiplicative inverse to each other when αγ ≡ u.”
Source: Wiktionary, CC BY-SA 4.0
Used as a crossword answer2 curated clues
01“Dark core”5 letters
02“Inner shadow”5 letters
Not quite right?
"Search similar patterns."
U____