British Director Ronald Eyre kept the action crisp; he was correctly content to execute the composer's wishes, rather than impose a fashionably idiosyncratic view of his own.
She emerged as one of the great, idiosyncratic talents of the Nineties.
If you describe someone's actions or characteristics as idiosyncratic, you mean that they are rather unusual. a highly idiosyncratic personality. = eccentric
A reaction to a medication that is unusual and unpredictable, specific to a particular person. Unlike allergy, it can occur on first exposure to the medication, unlike a side effect, it affects only very few individuals