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Definition of "ortho-" []

  • Straight; upright; vertical: orthotropous. (prefix)
  • Perpendicular: orthorhombic. (prefix)
  • Correct; correction: orthopsychiatry. (prefix)
  • The most fully hydrated form of an acid or of its salts: orthoboric acid. (prefix)
  • Diatomic molecules in which the nuclei have the same spin direction: orthohydrogen. (prefix)

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.