wack·y (wăkē) also whack·y (wăkē, hwăkē)
adj. wack·i·er, wack·i·est also whack·i·er or whack·i·est
1. Eccentric or irrational: a wacky person.
2. Crazy; silly: a wacky outfit.
[Variant of whacky, probably from the phrase out of whack; see WHACK.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.