C15: from Latin dissuādēre, from dis-1 + suādēre to persuade
Word Origin and History for dissuade
v.
1510s, from Middle French dissuader and directly from Latin dissuadere "to advise against, oppose by argument," from dis- "off, against" (see dis-) + suadere "to urge" (see suasion). Related: Dissuaded; dissuading.