asynchronous

American  

[ey-sing-kruh-nuhs] / eɪˈsɪŋ krə nəs /

adjective

1. not occurring at the same time.

   The factory has two asynchronous production lines with end products paired in final assembly and shipped to buyers.

2. (especially in education) occurring or able to be completed independently according to a person’s own self-paced schedule or within a broad window of time, but not coordinated to be completed in real time with another participant.

   Distance learners may earn participation points by attending real-time video chats, or by posting messages and replies in asynchronous discussion boards.

3. Digital Technology. relating to or being a computer operation that can occur independently, without waiting for another event.

   Asynchronous responses are returned to the client side without blocking for the completion of the database processing request.

4. Computers, Telecommunications. of, relating to, or operating without the use of fixed-time intervals coordinated by a clock, as data transmitted one byte or character at a time.

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Usage

What does asynchronous mean? Asynchronous refers to something not occurring at the same time as another thing. The opposite of asynchronous is synchronous, which means “occurring at the same time” or “simultaneous.” A face-to-face conversation is considered synchronous, because people are communicating in real time, whereas corresponding over email and text message—where the recipient can respond at a later time—is asynchronous. Example: The server could only download updates for each game asynchronously, one after the other.

Other Word Forms

• asynchronously adverb

Etymology

Origin of asynchronous

First recorded in 1740–50; a- ⁶ + synchronous

Explanation

Events are asynchronous when they don't happen at the same time. If you pick up the crossword puzzle I started yesterday, we are working on it together but in an asynchronous fashion. Please do it in pencil. Asynchronous is the opposite of synchronous, which means happening at the same time. Think of “synchronous” as “in synch” and asynchronous as “out of synch.” If we're chatting on the phone, our communication is “synchronous.” We respond to each other immediately and when we hang up, the conversation's over. Email is asynchronous because we respond whenever it's convenient. In some cases this means never, which can be mighty convenient.

Example Sentences

This type of asynchronous, always-on capability separates claws from conventional AI chatbots where work happens in real time through back-and-forth exchanges.

From The Wall Street Journal • Mar. 18, 2026

Texting is asynchronous, but expectations are for immediate replies.

From The Wall Street Journal • Dec. 28, 2025

Our digital feeds are asynchronous, hindered by advertisements and algorithms that either show us exactly what we want or desperately try to turn us onto something new.

From Salon • May 22, 2025

The certification programs are each six months long and are asynchronous, an online system by which a student can learn on his or her own schedule.

From Los Angeles Times • Nov. 10, 2023

The machine is asynchronous for in-out operations, that is, the completion of an in-out operation initiates the following instruction.

From Preliminary Specifications: Programmed Data Processor Model Three (PDP-3) October, 1960 by Digital Equipment Corporation