INTROVERT

I. transitive verb Etymology: intro- + -vert (as in divert) Date: 1669 to turn inward or in upon itself: as, to concentrate or direct upon oneself, to produce psychological introversion in, II. noun Date: 1883 something (as the retractile proboscis of some worms) that is or can be drawn in especially by invagination, one whose personality is characterized by introversion