idiosyncratic

As a noun colloquialism

is a colloquial word or phrase; a common spoken expression, often regional.

As an adjective idiosyncratic is

peculiar to a specific individual; eccentric.

As adjectives the difference between idiocratic and idiosyncratic

is that idiocratic is peculiar in constitution or temperament; idiosyncratic while idiosyncratic is peculiar to a specific individual; eccentric.

Quaint is a related term of idiosyncratic.

As adjectives the difference between quaint and idiosyncratic

is that quaint is (obsolete) of a person: cunning, crafty while idiosyncratic is peculiar to a specific individual; eccentric.

As a noun quaint

is (archaic) the vulva.

As adjectives the difference between idiosyncratic and idiocentric

is that idiosyncratic is peculiar to a specific individual; eccentric while idiocentric is characterized by or denoting interest centered upon oneself or one's own ways, rather than upon others or the ways of others; self-centered.

As adjectives the difference between anomalous and idiosyncratic

is that anomalous is deviating from the normal; aberrant or abnormal while idiosyncratic is peculiar to a specific individual; eccentric.

Outlandish is a related term of idiosyncratic.

As adjectives the difference between outlandish and idiosyncratic

is that outlandish is bizarre, strange while idiosyncratic is peculiar to a specific individual; eccentric.

Idiosyncratic is a related term of abnormal.

As adjectives the difference between idiosyncratic and abnormal

is that idiosyncratic is peculiar to a specific individual; eccentric while abnormal is not conforming to rule or system; deviating from the usual or normal type .

As a noun abnormal is

a person or object that is not normal.

As adjectives the difference between idiosyncratic and selfish

is that idiosyncratic is peculiar to a specific individual; eccentric while selfish is holding one’s self-interest as the standard for decision making.

As adjectives the difference between idiosyncratic and insane

is that idiosyncratic is peculiar to a specific individual; eccentric while insane is exhibiting unsoundness or disorder of mind; not sane; mad; deranged in mind; delirious; distracted.

Queer is a related term of idiosyncratic.

As adjectives the difference between queer and idiosyncratic

is that queer is (now|slightly|dated) weird, odd or different; whimsical while idiosyncratic is peculiar to a specific individual; eccentric.

As a noun queer

is (colloquial) a person who is or appears homosexual, or who has homosexual qualities.

As a verb queer

is to render an endeavor or agreement ineffective or null.

As an adverb queer

is queerly.