1. The ability of two unrelated single strands of DNA or RNA to pair with each other and become double stranded, due to the coincidental matching of an adequate number of nucleotide base pairs between the single strands.

  2. In terms of genetics, the ability of one mutation to compensate for another, unrelated mutation. See also genetic complementation and cis-trans test.

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