| PERICARDIUM | The membranous sac enclosing the heart (11) |
| PERICARDITIS | Inflammation of the membranous sac enclosing the heart (12) |
| EPICARDIUM | Innermost layer of the membranous sac around the heart |
| TRACHEA | In anatomy, the membranous tube that conveys inhaled air from the larynx to the bronchi (7) |
| PARICARDITIS | Inflammation of the sac enclosing the heart (12) |
| CHESILBEACH | Shingle ridge in Dorset enclosing the Fleet lagoon |
| CORALCORRAL | Pen enclosing the Great Barrier Reef? |
| PTERODACTYL | Extinct flying reptile with membranous wings (11) |
| CYST | An abnormal membranous sac containing liquid or semi-solid substance (in or out of the body) (4) |
| BLADDERY | Like a distensible membranous sac |
| BLADDER | Membranous sac or football innard |
| CYSTS | Membranous sacs of abnormal character in the body (5) |
| AMNIOTICSAC | Membranous bag that contains and protects a foetus in the womb (8,3) |
| BLADDERS | Membranous sacs or soccer ball innards |
| AMNIA | Sac enclosing embryo, pl. |
| SEPAL | In botany, the typically green and leaf-like parts of the calyx of a flower, enclosing the petals (5) |
| CRANIUM | What is a name for the skull, especially the part enclosing the brain? (7) |
| THECA | The loose sheath enclosing the spinal cord (5) |
| SPATHE | In botany, a sheathing bract enclosing the flower or spadix of plants including the arum, day flower, palm, peace lily and crocus (6) |
| EVENTHORIZON | The spherical area around a black hole enclosing the space from which electromagnetic radiation cannot escape |
