Hemadsorption is similar to hemagglutination; it can refer to:

1. The clumping together of red blood cells to other cells or particles, or to substrates.
2. The sticking of red blood cells to cells which have been infected with certain types of hemagglutinating viruses.

From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.