curve ball or curve·ball (kûrvbôl′)
1. Baseball Any of several pitches that veer to the left when thrown with the right hand and to the right when thrown with the left hand.
2. Slang Something that is unexpected or designed to trick or deceive: That last question on the exam was a real curve ball.
pitch/throw (someone) a curve ball Slang
1. To mislead; deceive.
2. To cause to be surprised, especially unpleasantly so.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.