agglutination

noun3

1. •
   The act of uniting by glue or other tenacious substance; the state of being thus united; adhesion of parts.
2. •
   The clumping together of red blood cells or bacteria, usually in response to a particular antibody.
3. •
   Combination in which root words are united with little or no change of form or loss of meaning. See agglutinative.