| MUSCLE | In anatomy, contractile structure such as the psoas whose mobility is provided by myosins and its energy primarily by mitochondria (6) |
| ONHOLIDAY | In French, it's "en vacances" (2,7) |
| OSTEOPATHS | They treat bones and muscles — doctoring to the psoas? |
| CATATONIA | Lack of mobility is first of troubles for Left in Spanish region (9) |
| MONUMENT | From the Latin meaning "remind", a commemorative structure such as the Cenotaph in Whitehall; or, a building of historical importance (8) |
| CHIASMA | Crossing over of two parts or structures such as the fibres of the optic nerves in the brain |
| ARIL | Botanical structure such as the mace surrounding nutmeg, ruby "jewel" of a pomegranate pip or the scarlet "berry" cup of a yew seed (4) |
| TOWER | Structure such as the Shard, Gherkin, Space Needle or Long Ta (5) |
| CLOCKTOWER | Building/structure such as the one housing Big Ben (5,5) |
| ARCH | Structure such as The Gateway of India |
| STYLET | Hard anatomical structure, such as the mouthpart of an aphid (6) |
| WORK | Energy transfer measured in joules; a creation such as a book, musical composition or piece of embroidery, sewing etc; or, a structure such as a wall, built as part of a fortification (4) |
| SCALA | A ladder-like structure, such as one of the spiral canals in the cochlea |
| ACTIN | Protein that combines with myosin to form the contractile filaments in muscle tissue (5) |
| OILRIG | Offshore structure such as Piper Alpha, which was destroyed by fire in 1988 (3,3) |
| BRIDGE | Structure such as an early "clam" or "clapper" type, built to span a divide or obstacle such as a river (6) |
| ATOMIC | --- bomb, type of weapon in which the energy is provided by nuclear fission (6) |
| NEWSAGENTS | In the New South Africa, men's loo is provided by shopkeepers (10) |
| SHELL | A structure such as a coconut's husk, a pea's pod, a pie's crust, a snail's exoskeleton or tortoise's carapace; or, a class that originally met in the apse of Westminster School (5) |
| ENGINEER | Originally a builder of fortifications, siege artillery and mechanical weapons such as trebuchets, later a designer/maker of machinery or structures such as bridges or roads (8) |
