tr.v. thwart·ed, thwart·ing, thwarts
1. To prevent the occurrence, realization, or attainment of: They thwarted her plans.
2. To oppose and defeat the efforts, plans, or ambitions of (someone).
1. A seat across a boat on which a rower may sit.
2. A transverse strut in a canoe or other small boat.
1. Extending, lying, or passing across; transverse.
2. Eager to oppose, especially wrongly; perverse.
adv. & prep.
[Middle English thwerten, from thwert, across, from Old Norse thvert, neuter of thverr, transverse; see terkw- in the Appendix of Indo-European roots.]
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.