Polypore. Very large. Same one as posted a few days ago, this time showing the undersurface and a closeup of the irregular pores which are quite large measuring 3 or 4 per mm. Spore print unobtainable due to high moisture content. Specimen in dryer.
Something that comes to mind is Rigidoporus laetus. Though maybe a little thin on the edge?! With this species you often see droplets of fluid suspended below the developing pores...