Definition of "all there"

all there

adjective
1. (idiomatic) Mentally competent; not absent-minded or insane.
  Quotations
  A suspicion that “he was not all there,” and therefore “one of God’s bairns,” had insured him, during his long orphanage, the food, and clothes, and shelter, necessary for life; but no one had given him love.
  1885, Amelia E. Barr, chapter 1, in Jan Vedder's Wife
  His submission is that he is of Mongolian extraction and irresponsible for his actions. Not all there, in fact.
  1922 February, James Joyce, “[Episode 15]”, in Ulysses, Paris: Shakespeare and Company, […]
  [S]he smiled at me in a such a silly way, I thought to wonder if she was all there.
  2011, Julie Keith, The Devil Out There, Part 1 (Google preview)
2. Used other than figuratively or idiomatically: see all,‎ there.