An aerosol for dispensing a liquid, in particular in the form of a foam, at least including a liquid container and a dispensing assembly which is coupled thereto. The dispensing assembly includes a liquid pump and an actuating head, the actuating head having a closed, circumferential protective cap. The aerosol furthermore includes a circumferential recess, into which the protective cap can move, which recess includes a closed inner wall, an outer wall and a base, and one or more outlet openings are present in the vicinity of the base of the recess, wherein the shape of the recess is such that the inner wall, on the side which is remote from the base, is at a radial distance p from the protective cap, which distance p is greater than the usual clearance distance of the protective cap with respect to the inner wall.