Nursing Central is an award-winning, complete mobile solution for nurses and students. Look up information on diseases, tests, and procedures; then consult the database with 5,000+ drugs or refer to 65,000+ dictionary terms. Explore these free sample topics:
-- The first section of this topic is shown below --
1. A device or substance used to indicate or mark something.
2. An identifying characteristic or trait that allows apparently similar materials or disease conditions to be differentiated.