Definition of "idiosyncratic"

At the time, I set it down to some idiosyncratic, personal distaste . . but I have since had reason to believe the cause to lie much deeper in the nature of man.

1886, Robert Louis Stevenson, chapter 9, in Dr. Jekyll and Mr. Hyde

It was no merely idiosyncratic experience, for the youth had the same: it was love!

1891, George MacDonald, chapter 12, in The Flight of the Shadow

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.

1982 April 26, Michael Walsh, “Music: A Fresh Falstaff in Los Angeles”, in Time

I’m not saying that Kaufman’s film will be enshrined as a classic, as those Kubrick films are. It’s too idiosyncratic and demanding for that: many viewers will be thinking of ending it halfway through

2020 September 1, Nicholas Barber, “Five stars for I'm Thinking of Ending Things”, in BBC‎