Meaning

verb come down on or keep down by unjust use of one's authority

verb cause to suffer

originFrom Middle English oppressen, from Old French oppresser, from Medieval Latin oppressare (“to press against, oppress”), frequentative of Latin opprimere, past participle oppressus (“to press against, press together, oppress”), from ob (“against”) + premere, past participle pressus (“to press”); see press.

Etymology from Wiktionary, CC BY-SA 3.0