Adjective

(en adjective)

Peculiar to a specific individual; eccentric.

* 1886 , (Robert Louis Stevenson), Dr. Jekyll and Mr. Hyde , ch. 9:

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.

* 1891 , (George MacDonald), The Flight of the Shadow , ch. 12:

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

* 1982 , Michael Walsh, " Music: A Fresh Falstaff in Los Angeles," Time , 26 April:

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.

Adjective

(en adjective)

Holding one’s self-interest as the standard for decision making.

* 1997 , John Peniel, The Children Of The Law Of One & The Lost Teachings Of Atlantis , chapter 10, page 127

“We all have both a selfish separate self, and an Inner Being that is One with the Universal Spirit. In this sense, every human has a sort of ‘split personality’. We are all kind of what you call ‘schitzy’ with these two sides, these two people living within us. And they are in total opposition. The free will dictates which of these two sides will have its way in our life, at every given moment.”

Having regard for oneself above others’ well-being.

*{{quote-book, year=1922, author=(Ben Travers)

, chapter=5, title= A Cuckoo in the Nest , passage=The most rapid and most seductive transition in all human nature is that which attends the palliation of a ravenous appetite.