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.
What does pH stand for and. To answer what does pH stand for is pretty straight forward. The p stands for potential and H stands for hydrogen. The definition of pH is the negative logarithm of the hydrogen (H+) ion activity in a given solution. By virtue of its logarithmic nature, pH is a dimensionless quantity. The purpose of the negative sign in the equation is to give a positive pH value.