1. Threefold; triple.
a. Of or relating to an astrologically favorable positioning of two celestial bodies 120° apart.
b. In astrology, situated 120° apart.
1. A group of three.
2. In astrology, the aspect of two planets when 120° apart.
3. Trine Christianity See Trinity.
[Middle English, from Old French, from Latin trīnus, sing. of trīnī, three each; see trei- 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.