N-COUNT(可数名词) 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. 深吸的一大口(空气或香烟等) [书面][usu N 'of' n]
I bobbed to the surface and gasped a lungful of air.
我浮上水面,深吸了一口气。