mid-14c., oppressioun, "cruel or unjust use of power or authority," from Old French opression (12c.), from Latin oppressionem (nominative oppressio) "a pressing down; violence, oppression," noun of action from past-participle stem of opprimere "press against, press together, press down;" figuratively "crush, put down, subdue, prosecute relentlessly" (in Late Latin "to rape"), from assimilated form of ob"against" (see ob-) + premere "to press, hold fast, cover, crowd, compress" (from PIE root *per- (4) "to strike").
Meaning "action of weighing on someone's mind or spirits" is from late 14c. Sense of "whatever oppresses or causes hardship" is from late 14c. In Middle English also "rape."
Proto-Indo-European root meaning "to strike," an extended sense from root *per- (1) "forward, through."
It forms all or part of: compress; depress; espresso; express; impress (v.1) "have a strong effect on the mind or heart;" imprimatur; imprint; oppress; oppression; pregnant (adj.2) "convincing, weighty, pithy;" press (v.1) "push against;" pressure; print; repress; reprimand; suppress.
mid-14c., persecucioun, "oppression for the holding of a belief or opinion," from Old French persecucion "persecution, damage, affliction, suffering" (12c.) and directly from Latin persecutionem (nominative persecutio), noun of action from past-participle stem of persequi "to follow, pursue, hunt down; proceed against, prosecute, start a legal action," from per "through" (from PIE root *per- (1) "forward," hence "through") + sequi "follow" (from PIE root *sekw- (1) "to follow").
General senses of "malevolent oppression, harassing or oppressive treatment," also "a time of general or systematic oppression" are from late 14c. Psychological persecution complex in reference to an irrational sense of being victimized by malign forces as a feature of a mental disorder is recorded from 1961; the earlier phrase for it was persecution mania (1892).
"a state of affliction or oppression, suffering, distress," c. 1200, from Old French tribulacion (12c.), from Church Latin tribulationem (nominative tribulatio) "distress, trouble, affliction," noun of action from past-participle stem of tribulare "to oppress, afflict," a figurative use by Christian writers of Latin tribulare "to press," also possibly "to thresh out grain," from tribulum "threshing sledge," from stem of terere "to rub" (from PIE root *tere- (1) "to rub, turn") + -bulum, suffix forming names of tools.
late 14c., constreinte, "distress, oppression," a sense now obsolete, from Old French constreinte "binding, constraint, compulsion" (Modern French contrainte), fem. noun from constreint, past participle of constreindre, from Vulgar Latin *constrinctus, from Latin constrictus, past participle of constringere "to bind together, tie tightly, fetter, shackle, chain," from assimilated form of com "with, together" (see con-) + stringere "to draw tight" (see strain (v.)).
Meaning "coercion, compulsion, irresistible force or its effect to restrict or compel" is from 1530s. Especially "repression of emotion or of the expression of one's thoughts or feelings" (1706).