chaffweed Syllabification: (chaff·weed)Pronunciation: /ˈCHafˌwēd/Definition of chaffweed noun a tiny European pimpernel with pink or white flowers. Anagallis minima, family Primulaceae Origin: mid 16th century: probably from the verb chafe + weedchaffweed in other Oxford dictionaries Definition of chaffweed in the British & World English dictionary