allelopathyPronunciation: /ˌaliːˈlɒpəθi/Definition of allelopathy noun [mass noun] Ecology the chemical inhibition of one plant (or other organism) by another, due to the release into the environment of substances acting as germination or growth inhibitors. Derivatives allelopathicPronunciation: /əˌliːlə(ʊ)ˈpaθɪk/ adjective Origin: 1950s: from Greek allēl- 'one another' + -pathyallelopathy in other Oxford dictionaries Definition of allelopathy in the US English dictionary