from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. That which the immune system identifies as foreign to the body.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. Any entity other than oneself.
  • n. All agents and substances that are not body's own.

from the GNU version of the Collaborative International Dictionary of English

  • n. That which is not oneself.
  • n. Any material that enters the body and is not recognized by the immune system as being part of its body, thereby triggering an immune response; any material appearing to the immune system to be foreign to its body.


Sorry, no etymologies found.



Log in or sign up to get involved in the conversation. It's quick and easy.