No, the word 'idiosyncratic' is an adjective, a word used to describe a noun as a way of behaving or thinking that is characteristic of a person or a thing.
The related noun form is idiosyncrasy.
Everyone has there own idiosyncratic ways about them.
Idiosyncratic: Strange or peculiar.AdjectiveShe emerged as one of the great idiosyncratic talents of the Nineties.Of the great idiosyncraticdetectives of fiction, NeroWolfe is my favourite.
Stop being so idiosyncratic, and actually do good on your tests.
Her idiosyncratic way of speaking made her stand out in a crowd.
The cast of Idiosyncratic - 2013 includes: Johnny Melville Maike Moeller Bornstein
Some people believe that goth people are idiosyncratic, but they work so hard to be like each other.
A person with an idiosyncratic mind seeks to be original, to stand out of the crowd, to have an eccentric lifestyle and to be open-minded about anything. Other characteristics of a person with an idiosyncratic mind are abstract thinking, introversion, autonomy and sensitivity.
Eccentric, unusual, idiosyncratic.
Medical reactions unique to an individual
Idiosyncratic reaction
nausea after taking an antibiotic agent
Idiosyncratic speech would be the kind of speech which contains some unusual or distinctive feature that is used by the particular person who is speaking, which is not found in the speech of most other people.