Definition of "nonself" [non•self]

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

• "It seems to me there is one: the word nonself-referring."
• "If they did not exactly scream "nonself," these antigens at least whispered "not quite self," and did so loudly enough to attract notice from the immune system."
• "The dividing line between self and nonself is taken to be the skin."