Definition of "biomarker" [biomarker]

• Medicine See marker. (noun)
• Medicine A specific physical trait used to measure or indicate the effects or progress of a disease or condition: Biomarkers of aging include thinning of the hair and diminished elasticity of the skin. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Secondhand smoke exposure was validated further using a short-term biomarker of exposure-the Level of cot nine in the umbilical cord blood at the time of delivery."
• "The hunt is on for a so-called biomarker, a characteristic or substance—or, more likely, several substances—in the body that will indicate if someone is sleepy and, if so, how sleepy."
• "The new approach, called the biomarker test looks for indirect evidence of hgh use."