Definition of "underived" [underived]

• Not derived; basic: an underived postulate. (adjective)

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.

• "If it does give me a reason, it will because it is keyed in some way into an unvariable, underived reason."
• "So derived reasons are variable, and underived ones invariant."
• "On this account, counter-examples will only do damage if they are aimed at the supposed underived reasons."