sti·fling. adj. 1. Very hot or stuffy: The air was stifling in the closed room. 2. Inhibiting, stultifying, or oppressive: The scholarly correctness of our age can be stifling (Annalyn Swan).sti′fling·ly adv.. suffocating, close, oppressive, airless, sticky, muggy The stifling heat of the little room was beginning to make me nauseous.