The word(s) "oppress" appears 41 time(s) in 39 verse(s) in Quran in Mohsin Khan translation.

(11) Verily, Allah enjoins Al-'Adl (i.e. justice and worshipping none but Allah Alone - Islamic Monotheism) and Al-Ihsan [i.e. to be patient in performing your duties to Allah, totally for Allah's sake and in accordance with the Sunnah (legal ways) of the Prophet صلى الله عليه وسلم in a perfect manner], and giving (help) to kith and kin (i.e. all that Allah has ordered you to give them e.g., wealth, visiting, looking after them, or any other kind of help), and forbids Al-Fahsha' (i.e all evil deeds, e.g. illegal sexual acts, disobedience of parents, polytheism, to tell lies, to give false witness, to kill a life without right), and Al-Munkar (i.e all that is prohibited by Islamic law: polytheism of every kind, disbelief and every kind of evil deeds), and Al-Baghy (i.e. all kinds of oppression). He admonishes you, that you may take heed.

(12) And do not kill anyone whose killing Allah has forbidden, except for a just cause. And whoever is killed wrongfully (Mazluman intentionally with hostility and oppression and not by mistake), We have given his heir the authority [to demand Qisas, - Law of Equality in punishment - or to forgive, or to take Diyah (blood money)]. But let him not exceed limits in the matter of taking life (i.e he should not kill except the killer). Verily, he is helped (by the Islamic law).

(13) And (remember) when We told you: "Verily! Your Lord has encompassed mankind (i.e. they are in His Grip)." And We made not the vision which we showed you (O Muhammad as an actual eye-witness and not as a dream on the night of Al-Isra' ) but a trial for mankind, and (likewise) the accursed tree (Zaqqum, mentioned) in the Qur'an. We warn and make them afraid but it only increases them in naught save great disbelief, oppression and disobedience to Allah.

(14) "And as for the boy, his parents were believers, and we feared lest he should oppress them by rebellion and disbelief.

(15) (Saying) eat of the Tayyibat (good lawful things) wherewith We have provided you, and commit no transgression or oppression therein, lest My Anger should justly descend on you. And he on whom My Anger descends, he is indeed perished. [Tafsir At-Tabari]

(16) Then We fulfilled to them the promise. So We saved them and those whom We willed, but We destroyed Al-Musrifun (i.e. disbelievers in Allah, in His Messengers, extravagants, transgressors of Allah's limits by committing crimes, oppressions, polytheism and sins).

(17) And when you have embarked on the ship, you and whoever is with you, then say: "All the praises and thanks be to Allah, Who has saved us from the people who are Zalimun (i.e. oppressors, wrong-doers, polytheists, those who join others in worship with Allah).

(18) "Our Lord! Bring us out of this. If ever we return (to evil), then indeed we shall be Zalimun: (polytheists, oppressors, unjust, and wrong-doers)."

(19) And (remember) the Day when the Zalim (wrong-doer, oppressor, polytheist) will bite at his hands, he will say: "Oh! Would that I had taken a path with the Messenger (Muhammad صلى الله عليه وسلم).

(20) And none has brought us into error except the Mujrimun [Iblis (Satan) and those of human beings who commit crimes, murderers, polytheists, oppressors].