"in singular" is a correct phrase that can be used in written English.
You can use it to describe a single instance or occurrence. For example, "The colors were bright and vivid, each one in singular beauty."
(Again, he saw plenty of ghosts in singular form — I'm only making a point).
You have to admire the depth of the dancers' commitment in "Singular Sensation".
Such a plenitude, he claimed, could allow the Hermitage to experiment in singular ways.
The Way We Were Americans mostly think of themselves in singular racial terms.
"I am not interested in singular implications [in art]," he said.
By means of distinctive endings, the verb distinguished three persons in singular and plural.
Nouns were inflected for four cases (nominative, genitive, dative, and accusative) in singular and plural.
Edwin Morgan was a singular voice in a country with a literary tradition rich in singular voices.
But, in comparison with Old Armenian (where case endings were different in singular and plural), Modern Armenian declension resembles rather the Turkish or the Georgian type of agglutination.
These wars, like all wars, present complicated questions, ones that deserve sophisticated and honest answers, not boasts wrapped in singular solutions.
As war secretary in 1920, Churchill described the shootings as "a monstrous event, an event which stands in singular and sinister isolation".
