| INERTIAL | The mass of the body that measures its Inertia (8) |
| OCTANE | Chemical in petrol that measures its quality |
| POPULACE | "Rhythmic music" - a clue to be solved by the mass of the people (8) |
| KILOGRAM | Metric unit of mass that is very nearly equal (it was originally intended to be exactly equal) to the mass of 1,000 cubic cm of water. The pound is defined as equal to 0.45359237 of this unit. (8) |
| OXYGEN | Accounting for 65 per cent of the mass of the human body, the third-most abundant element in the universe, atomic number eight (6) |
| SUN | Celestial body that constitutes more than 99% of the mass of the solar system |
| NEUTRINO | Roughly meaning "tiny, zero charge", a particle some six million times lighter than an electron, thus so small that no one has been able to measure its mass (8) |
| DARKMATTER | A large proportion of the mass of the universe (4,6) |
| EERIE | Like Homer Simpson predicting the mass of the Higgs boson within an order of magnitude fourteen years before CERN |
| SERVICE | It could be the mass of the army (7) |
| SCIENCES | Academy of Motion Picture Arts and ___, full name of the body that awards Oscars (8) |
| CRAFTIER | Announcer imbibing a small measure - it's shrewder |
| SHOULDER | Part of the body (that bears burdens?) (8) |
| INNEREAR | Part of the body that controls your balance |
| MOUSSE | French word first used in English to describe the mass of tiny bubbles on the surface of a glass of champagne, later for a light frothy whipped pudding, reminiscent of this (6) |
| DENSITY | The ratio of the mass of a substance to its volume (7) |
| WALDEN | Whence the line 'The mass of men lead lives of quiet desperation' |
| ENERGID | The nucleus of a cell together with the mass of protoplasm around it (7) |
| CHAFF | The mass of husks separated from the seeds of cereal grain during threshing (5) |
| SMILE | Beam: at first surveyor measures its length exactly |
