“+...- noun
Etymology: dichlor- + phenoxyacetic
: a white crystalline compound Cl 2 C 6 H 3 OCH 2 COOH made from 2,4-dichloro-phenol and chloroacetic acid that is a growth regulator for plants and is used especially in the form of salts and esters as a weed killer — usually used with initial numbers
2,4- dichlorophenoxyacetic acid
— called also 2,4-D