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isth·mus

(ĭsməs)

n. pl. isth·mus·esor isth·mi (-mī′)

1. A narrow strip of land connecting two larger masses of land.

2. Anatomy

a. A narrow strip of tissue joining two larger organs or parts of an organ.

b. A narrow passage connecting two larger cavities.

[Latin, from Greek isthmos, narrow passage, neck, isthmus, possibly from ienai, i-, to go; see ei- in the Appendix of Indo-European roots, or possibly of pre-Greek substrate origin.]

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:

Indo-European Roots

Semitic Roots

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.

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