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therm-

pref.

Variant of thermo-.

therm

(thûrm)

a. A unit of heat equal to 100,000 British thermal units (1.054 × 10⁸ joules).

b. A unit of heat equal to 1,000 large calories.

a. A unit of heat equal to the large calorie.

b. A unit of heat equal to the small calorie.

[Greek thermē, heat, from thermos, warm, hot; see g^wher- in the Appendix of Indo-European roots.]

-therm

suff.

An animal having a specified kind of body temperature: poikilotherm.

[From Greek thermē, heat, from thermos, warm, hot; see g^wher- in the Appendix of Indo-European roots.]

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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