A process that is invoked to generate a random sequence of values (usually a sequence of bits) or an individual random value.
Source(s):
CNSSI 4009-2015 from IETF RFC 4949 Ver 2

  A mechanism that purports to generate truly random data.
Source(s):
NIST SP 800-22 Rev. 1a under Random Number Generator (RNG)

  A process used to generate an unpredictable series of numbers. Also called a Random bit generator (RBG).
Source(s):
NIST SP 800-57 Part 1 Rev. 5 under Random number generator (RNG)
NIST SP 800-57 Part 1 Rev. 4 [Superseded] under Random number generator (RNG)

  A process used to generate an unpredictable series of numbers. Also, referred to as a Random bit generator (RBG).
Source(s):
NIST SP 800-57 Part 1 Rev. 3 [Superseded] under Random number generator (RNG)

  Produces a sequence of zero and one bits that is random in the sense, that there is no way to describe its output that is more efficient than simply listing the entire string of output. There are two basic classes: deterministic and non-deterministic. A deterministic RNG (also known as a pseudorandom number generator) consists of an algorithm that produces a sequence of bits from an initial value called a seed. A non-deterministic RNG produces output that is dependent on some unpredictable physical source that is outside human control, such as thermal noise or radioactive decay.
Source(s):
NIST SP 800-57 Part 2 [Superseded] under Random Number Generator (RNG)