1. Enclosed within a hard shell, usually the skin of the last larval instar. Used of an insect pupa.
2. Constricted, narrowed, or compressed, as a segment of a blood vessel.
[Latin coarctātus, past participle of coarctāre, to compress, alteration of coartāre : co-, co- + artāre, to compress (from artus, tight, confined; see ar- in the Appendix of Indo-European roots).]
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.