A surgical instrument with a cylindrical saw usually used for removing a disk of bone, especially from the skull, or for removing corneal tissue.
tr.v. tre·phined, tre·phin·ing, tre·phines
To operate on with a trephine.
[French tréphine, from obsolete English trefine, from Latin trēs fīnēs, three ends : trēs, three; see trei- in the Appendix of Indo-European roots + fīnēs, pl. of fīnis, end.]
treph′i·nation (trĕf′ə-nāshən) n.
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.