1660s, "restrained, checked," past-participle adjective from repress (v.). Psychological sense of "kept out of the conscious mind, kept in the subconscious" is attested by 1904.
Entries linking to repressed
repress v.
late 14c., "to check, restrain (sin, error); to overcome, put down, subdue (riot, rebellion);" from Latin repressus, past participle of reprimere "hold back, curb," figuratively "check, confine, restrain, refrain," from re- "back" (see re-) + premere "to press, hold fast, cover, crowd, compress" (from PIE root *per- (4) "to strike").
Used of feelings or desires from late 14c.; in the purely psychological sense "keep out of the conscious mind, keep in the subconscious" it represents German verdrängen (Freud, 1893), that sense of the word first attested in English in 1904 (implied in repressed). Related: Repressed; repressing.