suppressor mutation

[sə-prĕsər]
n.
  1. A mutation that alters the anticodon in a tRNA so that it is complementary to a termination codon, thus suppressing termination of the amino acid chain.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.