umbra
noun/ˈʌmbɹə/
Etymology Borrowed from Latin umbra (“shadow”). Doublet of umber.
8 senses
- 1The fully shaded inner region of a shadow cast by an…
- 2The area on the earth or moon experiencing the total…
- 3The central region of a sunspot.
- 4A shadow.
- 5An uninvited guest brought along by one who was invited.
- 6One of the family Umbridae of mudminnows.
- 7One of genus Umbrina of drums (family Sciaenidae).
- 8An element of the umbral calculus.
1
The fully shaded inner region of a shadow cast by an opaque object.
2
Astronomy, Natural sciences The area on the earth or moon experiencing the total phase of an eclipse.
3
Astronomy, Natural sciences The central region of a sunspot.
4
Literary A shadow.
5
Archaic An uninvited guest brought along by one who was invited.
6
One of the family Umbridae of mudminnows.
7
One of genus Umbrina of drums (family Sciaenidae).
8
Mathematics, Sciences An element of the umbral calculus.
- 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.2009, Ernesto Damiani, Ottavio D'Antona, Vincenzo Marra, From Combinatorics to Philosophy: The Legacy of G.-C. Rota, (page 113)#:
- Derived terms
- adumbrate, antumbra, Bernoulli umbra, penumbra, umbral, umbraphile, umbra recta, umbration, umbra versa, umbrella