Know how to use "fewer" and "less"? Find out.
1916, extravert (spelled with -o- after 1918, by influence of introvert), from German Extravert, from extra "outside" (see extra-) + Latin vertere "to turn" (see versus).
With introvert, words that had been used in English by doctors and scientists in various literal senses since 1600s, but popularized in a psychological sense by Carl Jung. Related: Extroverted.
extrovert ex·tro·vert or ex·tra·vert (ěk'strə-vûrt')
An individual interested in others or in the environment as opposed to or to the exclusion of self.
A term introduced by the psychologist Carl Jung to describe a person whose motives and actions are directed outward. Extroverts are more prone to action than contemplation, make friends readily, adjust easily to social situations, and generally show warm interest in their surroundings. (Compare introvert.)