addictant adjective 1noun 1forms 3 adjective1 •Capable of causing addiction, addictiveProcaine and the related synthetic local anesthetics are not addictant. — 1957 noun1 •An addictive substanceFurthermore, the frequency and size of the dosage of the addictant determine the extent of addiction. — 1981 formsaddictants · more addictant · most addictant