unforeseen

adjective

un·​fore·​seen ˌən-fȯr-ˈsēn 

: not anticipated or expected : not foreseen : unexpected

an unforeseen delay

unforeseen consequences

Synonyms of unforeseen

• sudden
• unexpected

Examples of unforeseen in a Sentence

there are almost always unforeseen consequences for any major endeavor

unforeseen problems delayed the project beyond its deadline

Recent Examples on the Web

Although an unforeseen event may have taken their lives, their bones were preserved for over 200 million years. —Maria Mocerino, Interesting Engineering, 3 May 2026

Banks must test full workflows and inter-agent interactions, where unforeseen risks emerge. —Jeffrey Sonnenfeld, Fortune, 2 May 2026

This has been a story of unforeseen incidents, such as the unnoticed approach of the storm and the capsizing in front of high cliffs that prevented us from swimming ashore before the cold water had weakened us. —Jim Hoagland, Outdoor Life, 30 Apr. 2026

But the tiny new form factor quickly introduced other unforeseen problems. —Mack Degeurin, Popular Science, 30 Apr. 2026

Word History

First Known Use

1651, in the meaning defined above

Rhymes for unforeseen

• acetylene
• adenosine
• amphetamine
• anthropocene
• antipyrine
• apomorphine
• apoprotein
• aquamarine
• arsphenamine
• azobenzene
• buprenorphine
• chlorobenzene