What might be the earliest-known entry of the word "algorithm" in a dictionary can be found in Samuel Johnson's Dictionary of the English Language from 1785.
The entry on page 130 reads (approximately):
algorithm: arabic words which are used to imply the six operations of arithmetic or the science of numbers.
Today, "algorithm" is defined as:
- A well-defined procedure to solve a problem.
- A clearly specified set of simple instructions to be followed to solve a problem.
- A finite, deterministic, and effective problem-solving method.