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.


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