The Collaborative International Dictionary of English v.0.48:
Nor \Nor\ (n[^o]r), conj. [OE. nor, contr. from nother. See
A negative connective or particle, introducing the second
member or clause of a negative proposition, following
neither, or not, in the first member or clause (as or in
affirmative propositions follows either). Nor is also used
sometimes in the first member for neither, and sometimes the
neither is omitted and implied by the use of nor.
Provide neither gold nor silver, nor brass, in your
purses, nor scrip for your journey. --Matt. x. 9,
Where neither moth nor rust doth corrupt. --Matt. vi.
I love him not, nor fear him. --Shak.
Where neither party is nor true, nor kind. --Shak.
Simois nor Xanthus shall be wanting there. --Dryden.
The Free On-line Dictionary of Computing (18 March 2015):
The Boolean function which is true if none of its inputs are
true and false otherwise, the logical complement of
inclusive OR. The binary (two-input) NOR function can be
defined (written as an infix operator):
A NOR B = NOT (A OR B) = (NOT A) AND (NOT B)
Its truth table is:
A | B | A NOR B
F | F | T
F | T | F
T | F | F
T | T | F
NOR, like NAND, forms a complete set of Boolean functions on
its own since it can be used to make NOT, AND, OR and any
other Boolean function:
NOT A = A NOR A
A OR B = NOT (A NOR B)
A AND B = (NOT A) NOR (NOT B)