The phrase "an unprecedented development" is correct and usable in written English.
It can be used to describe a situation or event that is unique and has not occurred before, often in a significant or impactful context.
Example: "The discovery of a new species in the urban area is considered an unprecedented development in the field of urban ecology."
Alternatives: "a groundbreaking event" or "an extraordinary occurrence".
"Lake Columbia is really an unprecedented development".
In an unprecedented development tanker lorries from other parts of the country are now supplying Oujda.
In an unprecedented development, the national basketball team – widely seen as the soul of any Greek Olympics delegation – failed to make it.
WASHINGTON (The Borowitz Report) — In what historians are calling an unprecedented development in American politics, both major parties decided today to cancel the 2012 election.
By Andy Borowitz June 19 , 2012WASHINGTON (The Borowitz Report) — In what historians are calling an unprecedented development in American politics, both major parties decided today to cancel the 2012 election.
"We have already had significant international interest shown in developing the site, and we anticipate that global investors will be excited about what is an unprecedented development opportunity," Mr. Brannigan said.
This would have been a radical, unprecedented development; Selig had promised the union that he would not invoke this power.
The Qatar government declined to comment on our report, but those close to it point out that patience is required in a country grappling with a period of unprecedented development and growth, and which relies on support from foreign workers like few other places on earth.
In the quick popularity and promoting function of micro-computer and internet, human-computer researches have unprecedented development and develop towards more intellect, convenient, human orientated direction.
This is facilitated by the second unprecedented development, an internet which makes information available at the grass roots level and gives people the ability to demand change.
As Geoffrey Kabaservice asserts in Rule and Ruin: "The appearance of a Republican party almost entirely composed of ideological conservatives is a new and historically unprecedented development.
