"deprive of contentment, late 15c., from dis- "not, reverse of" + content (v.). Perhaps from Old French descontenter. Related: Discontented; discontentedly; discontentment; discontentedness.
"unquiet in mind through having one's desires unsatisfied," mid-15c., from dis- "opposite of" + content (adj.).
"state or feeling of mental dissatisfaction, uneasiness of mind," 1580s, from dis- "opposite of" + content (n.). Winter of our discontent is from "Richard III" (1594).