| ANTRUM | Natural chamber or cavity in a bone or other anatomical structure, e.g. a sinus (6) |
| SINUS | Cavity in a bone or other tissue (5) |
| GROTTO | Natural chamber |
| AEROFOIL | A structure, eg a wing, with curved surfaces to reduce drag and generate lift (8) |
| TENDON | A cord of fibrous tissue attaching a muscle to a bone or other structure (6) |
| PIT | Hole or cavity in the ground |
| ENT | Doctor that may diagnose a sinus infection (abbr.) |
| SINEW | A strong cord connecting a muscle with a bone or other part (5) |
| COFFER | From "chest, basket", a strongbox for valuables; a watertight chamber; or, a sunken lacunar in a ceiling (6) |
| SPILLS | Causes (liquid) to swirl round in a container or cavity (6) |
| STRESS | ___ fracture, slight break in a bone from repetitive jarring, common in athletes (6) |
| ESTUFA | From "heat by steam", a Spanish or Portuguese heat-centric word for a cooker, oven, stove, hothouse, Pueblo Indian kiva-like assembly room, sauna, Madeira-maturing chamber or wine-warming cellar (6) |
| MARROW | Large vegetable, or fatty filling in a bone (6) |
| STYLET | Hard anatomical structure, such as the mouthpart of an aphid (6) |
| CRATER | Bowl-shaped cavity, in a volcano say (6) |
| LACUNA | Small pit or cavity (6) |
| CARIES | Progressive decay of a bone or tooth |
| AIRSAC | Cavity in a lung |
| TUBULE | Small, cylindrical anatomical structure |
| CONCHA | Shell-like anatomical structure |
