The phrase "a single unexpected" is not correct in written English as it lacks a noun to complete the thought.
It can be used in contexts where you want to describe an unexpected event or outcome, but it needs to be part of a larger phrase.
Example: "The experiment yielded a single unexpected result that changed our understanding of the phenomenon."
Alternatives: "one unforeseen" or "a solitary surprise".
Many dishes are pushed toward extraordinary by the addition of a single, unexpected ingredient.
It was a strange feeling, on Thursday, to do laps around a bookstore without feeling a single unexpected thrill.
Today, there is a move away from such articles and toward one-experiment papers reporting a single unexpected result.
And then to do the most meaningful thing: with a single unexpected movement turn her around and knock her on her stomach– so that his nose could hang into her arching, sweet little ass.
Her eyes, like those of a gazelle, could have pierced a thousand hearts with a single unexpected glance, yes, with one flicker of her eyelashes she could have slain a whole world".
In a single, unexpected stroke, the deal also achieves the disparate objectives of the group of politicians, regulators and businessmen who were tossed into a debate by the mixmaster of San Francisco politics.
So, while I covered the meeting, I focused on finding that single, unexpected thing.
An entire career can be lost in a single gaffe or an unexpected shift in the national mood.
Engineers say the people who manage the transmission system set limits on how much power can be pumped through a particular line based on having the system survive a single failure, not an unexpected combination of failures.
Few communities have experienced such a collective nightmare — not a blitz or a siege or a carpet bombing, but a single, sudden, unprovoked, totally unexpected, criminally murderous onslaught upon an undefended target.
According to JR, his art "doesn't change the world, but sometimes a single laugh in an unexpected place makes you dream that it could".
