introversion

noun4

1. •
   A turning inward.

   • This disease is sometimes produced by the introversion of the edge of the lower eyelid. — 1796
2. •
   A personality orientation towards the self and mental abstraction; behavior expressing such orientation.

   • ...so that when in later life there occurs an introversion (in the sense of Jung), it consists of a harking back to regressive, reminiscent, infantile material. — 1912
3. •
   The action of turning one's thoughts upon internal or spiritual matters.

   • ...their... Fastings, Prayings,... Introversions,... Humiliations, Mortifications... — 1654
4. •
   Arrangement of two similar words, lines, etc. to form the middle part of a structure.

   • Such introversion is merely a matter of form. — 1896