An eccentric person is someone who behaves or thinks in an unusual way that might seem strange to others. They often do things differently from what's considered normal.
Eccentric people are those who have unique personalities and habits, sometimes even quirky or weird ones. We usually use this word to describe a friend, family member, or celebrity who does something unexpected, like wearing outrageous outfits, having an unusual hobby, or saying outlandish things. For example, if your neighbor has a house that's decorated with all sorts of peculiar items and they're always coming up with strange theories about life, you might say they're a bit eccentric. Sometimes we also use the word to describe something that's a little offbeat, like an art project or a movie plot.
How common is "eccentric"?
Word eccentric is considered uncommon in modern English. It has a balanced usage among all categories: speech, fiction, newspapers and academic texts.
Definitions
adjective
Not at or in the centre; away from the centre.
Not perfectly circular; elliptical.
Example: As of 2008, Margaret had the most eccentric orbit of any moon in the solar system, though Nereid's mean eccentricity is greater.
Having a different center; not concentric.
(of a person) Deviating from the norm; behaving unexpectedly or differently; unconventional and slightly strange.
Example: 1801, Author not named, Fyfield (John), entry in Eccentric Biography; Or, Sketches of Remarkable Characters, Ancient and Modern, page 127,
He was a man of a most eccentric turn of mind, and great singularity of conduct.
(physiology, of a motion) Against or in the opposite direction of contraction of a muscle (such as results from flexion of the lower arm (bending of the elbow joint) by an external force while contracting the triceps and other elbow extensor muscles to control that movement; opening of the jaw while flexing the masseter).
Having different goals or motives.
Example: a. 1626, Francis Bacon, 1867, Richard Whately (analysis and notes), James R. Boyd (editor), Essay XI: Wisdom for a Man's Self, Lord Bacon's Essays, page 171,
[…] for whatsoever affairs pass such a man's hands he crooketh them to his own ends, which must needs be often eccentric to those of his master or state: […]
(mycology) Having or being an oospore with a single large oil globule on one side that displaces much of the ooplasm and forces the ooplasts to one side.