N-COUNT (新鲜空气、香烟等)深吸的一大口 If someone takes a lungful of something such as fresh air or smoke, they breathe in deeply so that their lungs feel as if they are full of that thing. (新鲜空气、香烟等)深吸的一大口 [written]
I bobbed to the surface and gasped a lungful of air. [+ of]