detrimental /ˌdɛtɹɪˈmɛntəl/adjective 1noun 1forms 3 adjective1 •Causing damage or harm.Smoking tobacco can be detrimental to your health. noun1 •Anything harmful.The definition of a parasite is a microbe that lives in you or on you to its benefit and to your detriment. In other words, the detrimentals suck the life out of you. — 2012 formsdetrimentals · more detrimental · most detrimental