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.
synergy synÂ·erÂ·gy (sÄ­n'Ér-jÄ) n. The interaction of two or more agents or forces so that their combined effect is greater than the sum of their individual effects.