not occurring at the same time.
(of a computer or other electrical machine) having each operation started only after the preceding operation is completed.
Computers, Telecommunications. of or relating to operation without the use of fixed time intervals (opposed to synchronous).
Origin of asynchronous
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
1748, from a-, privative prefix, + synchronous.
Online Etymology Dictionary, © 2010 Douglas Harper