al·le·lop·a·thy (ə-lē-lŏpə-thē, ăl′ə-)
A usually negative effect on the growth or development of an organism of one species, caused by a chemical released by an organism of another species. Usually used of plants.
[Greek allēlōn, reciprocally (from allos, another; see al-1 in the Appendix of Indo-European roots) + -PATHY.]
al·le′lo·pathic (ə-lē′lə-păthĭk, ə-lĕl′ə-) adj.
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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.