Qui n'est pas synchrone.
ETYM Greek a- not + synchronous.
1. Not synchronous; not occurring or existing at the same time or having the same period or phase.
2. (Digital communication) Pertaining to a transmission technique that does not require a common clock between the communicating devices; timing signals are derived from special characters in the data stream itself.
Not occurring at same time.
Irregular or not synchronized. In computer communications, the term is usually applied to data transmitted irregularly rather than as a steady stream. Asynchronous communication uses start bits and stop bits to indicate the beginning and end of each piece of data.
Pertaining to, being, or characteristic of something that is not dependent on timing. For example, asynchronous communications can start and stop at any time instead of having to match the timing governed by a clock.