What does unsynchronised mean?
Unsynchronised means not synchronized: two or more clocks, devices, signals, events, or parts of a system do not operate in precise agreement in time. The word appears especially in technical discussions of electronics, computing, broadcasting, transport, and coordinated processes, where even a small timing discrepancy may matter. It can also be used more broadly for people, actions, or efforts that lack coordination, though that use can sound formal and occasionally implies blame for poor planning. In everyday conversation, “out of sync” usually expresses the same idea more casually. “Unsynchronised” is chiefly associated with British spelling, while US English commonly uses “unsynchronized”; both are pronounced similarly. The term is useful when precision matters because it distinguishes simple disagreement or delay from a specific failure to align in time. For example, two clocks may each be accurate yet remain unsynchronised if they display different times. In media and systems engineering, the same word identifies independently running components whose phases or timing are not matched.
Not synchronized; lacking agreement or coordination in timing.
"The backup generators were unsynchronised and therefore operated independently."
The dominant use of the word, especially in technical contexts.
To cause something to lose synchronization, or to fail to remain synchronized.
"The editor unsynchronised the sound and picture to create a deliberate echo."
Less common than the adjectival use and chiefly British.
Two clocks can both be perfectly accurate and still be unsynchronised: each may be right while telling different times.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does unsynchronised come from?
Unsynchronised combines the English prefix un-, meaning “not,” with synchronise. Synchronise came through French synchroniser from Greek synchronos, meaning “simultaneous” or “happening at the same time,” and was ultimately formed from Greek elements meaning “together” and “time.” Related English words include synchronous, synchrony, synchronisation, and asynchronous.
Related word forms
How unsynchronised is actually used
The spelling is chiefly British; US English usually uses unsynchronized. The word has a formal or technical tone, while the everyday alternative is 'out of sync'.
Easily confused with unsynchronised
Asynchronous describes something designed or operating without synchronized timing, whereas unsynchronised more often describes devices, signals, or events that have failed to align in time.
Unsynchronized is the usual US spelling of the British form unsynchronised; the meaning is the same.