Thayer's Greek Lexicon

 1. to cause to coalesce, to join together, put together
  1) to unite or knit together: in affection
2. to put together in one's mind
  1) to compare
  2) to gather, conclude, consider
3. to cause a person to unite with one in a conclusion or come to the
same opinion, to prove, demonstrate
  1) to teach, instruct, one