biosignature

noun

bio·​sig·​na·​ture ¦bī-(ˌ)ō-¦sig-nə-ˌchu̇r+ 

plural biosignatures

: something (such as a chemical compound, isotope, or cellular component) that indicates or suggests the presence of a biological process indicative of life

This will help astronomers learn to recognize "biosignatures"—clues that a planet's atmosphere has been influenced by life.

—Karen Schmidt, New Scientist, 2 July 2005

… the potential of the microbes to become fossils and serve as "biosignatures" for researchers seeking signs of early life in the remnants of ancient volcanism and hydrothermal activity on Earth—and, particularly, on Mars.

—David Perlman, San Francisco Chronicle, 21 Apr. 2005

Word History

Etymology

bi- entry 2 + signature

First Known Use

1995, in the meaning defined above

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!