See baleen whale.
[New Latin mysticētus, from Greek mustikētos, textual transmission error (found in early modern editions of Aristotle's Historia animalium) of the phrase (ho) mūs to kētos, (the) whale (called) the mouse (Aristotle's designation for an unknown kind of aquatic animal) : mūs, mouse; see mūs- in the Appendix of Indo-European roots + to : neuter nominative and accusative singular definite article ; see to- in the Appendix of Indo-European roots + kētos, sea monster, whale (of unknown origin).]
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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.