A lid is provided for engagement with a projecting rim of an opening on a container. The lid includes a covering panel for closing the container opening and a skirt formed on a periphery of the cover and depending therefrom. The skirt overlaps with the container rim when the cover is positioned over the opening. The skirt includes a defined gap therein that is positioned between adjacent gap edges. A clasp is provided on the periphery of the cover adjacent the defined gap. The clasp pivots between an open position and an engaged position. In the engaged position, the clasp engages the gap edges and draws the edges toward one another. The drawing of the gap edges moves the skirt inwardly towards the container rim. The lid may further include a flexing portion defining a connection between the cover panel and the skirt. The engagement of the clasp on the skirt causes compliance of the flexing portion and a corresponding axial movement of the skirt relative to the cover panel.