inbreed Syllabification: (in·breed)Pronunciation: /ˈinˌbrēd/Definition of inbreed verb (past and past participle inbred) [no object] (often as noun inbreeding) breed from closely related people or animals, especially over many generations:persistent inbreeding has produced an unusually high frequency of sufferers from this diseaseinbreed in other Oxford dictionaries Definition of inbreed in the British & World English dictionary