Definition of ECCENTRIC in the Definitions.net dictionary. Meaning of ECCENTRIC . What does ECCENTRIC mean ? Information and translations of ECCENTRIC in the most comprehensive dictionary definitions resource on the web. You're most likely to encounter the adjective eccentric in a description of an unusual or quirky person — like a scatterbrained aunt who leaves her life savings to her cat. Eccentric definition: deviating from the recognized or customary character, practice, etc.; irregular; erratic; peculiar; odd.. See examples of ECCENTRIC used in a sentence. What does the word eccentric mean ? There are 18 meanings listed in OED's entry for the word eccentric , four of which are labelled obsolete. See ‘ Meaning & use’ for definitions, usage, and quotation evidence. eccentric