Medical Definition of narcissistic personality disorder. : a personality disorder characterized especially by an exaggerated sense of self-importance, persistent need for admiration, lack of empathy for others, excessive pride in achievements, and snobbish, disdainful, or patronizing attitudes.
For the purposes of sym metry, letâs now move on to the most common variant of syn- , or sym- , which also means âtogether.â A sym phony is the sounding âtogetherâ of many instruments.
sigma - the 18th letter of the Greek alphabet. Greek alphabet - the alphabet used by ancient Greeks. alphabetic character, letter of the alphabet, letter - the conventional characters of the alphabet used to represent speech; his grandmother taught him his letters. Translations. sigma.