The Oxford Thesaurus An A-Z Dictionary of Synonyms - oppressiveadj.

1) burdensome, overpowering, overwhelming, onerous, heavy, cumbersome, exhausting, racking, unbearable, intolerable, agonizing, unendurable, harsh, brutal, severe, tyrannical, repressive; dispiriting, depressing, disheartening, discouraging, grievous, distressing, dolorous, miserable, harrowing, wretched: The conquerors resorted to oppressive measures to keep the people subjugated. 2) suffocating, stifling, stuffy, close, airless, unventilated, uncomfortable: The atmosphere in the tiny cell quickly became oppressive, and a couple of people fainted.