| OBRECHT | Jacob -, composer of the mass Missa Maria zart who died in 1505 |
| MOMENTUM | In physics, the quantity of motion of a moving body, equal to the product of the mass and the velocity (8) |
| AGNUSDEI | What is the Latin name of the prayer Lamb of God. a part of the mass in the Catholic, Anglican and Lutheran liturgies? (5,3) |
| BEETHOVEN | Composer of Missa Solemnis and Fidelio who wrote about his deafness in a letter titled Heiligenstadt |
| 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) |
| ASPERGES | Rite of sprinkling holy water at the beginning of the Mass in the Catholic Church (8) |
| PALESTRINA | Giovanni Pierluigi da ___, 16th-century Italian composer who works include the Missa Papae Marcelli |
| EDLER | Joe _, played Zart in The Maze Runner (5) |
| BREVIARY | Book giving the regulations for the celebration of the Mass in Western Christianity (8) |
| INTROIT | Anthem sung at the beginning of the Mass in the Roman Catholic church (7) |
| MUSCOVY | Medieval principality of Russia of which Moscow was the capital, last ruled by Ivan III (1462-1505) (7) |
| IVANIII | Grand Duke of Muscovy 1462-1505 known as "the Great" (4,1,1,1) |
| DARKMATTER | A large proportion of the mass of the universe (4,6) |
| SUN | Celestial body that constitutes more than 99% of the mass of the solar system |
| DENSITY | The ratio of the mass of a substance to its volume (7) |
| ASTON | Scientist whose development of the mass spectrograph earned him the 1922 Nobel Prize in Chemistry (5) |
| IVAN | ___ the Great, leader of 1462-1505 |
| JOSQUIN | Judge unexpectedly pressed on with quiz: 'Who wrote Missa Fortuna desperata?' (7,3,4) |
| DESPREZ | Judge unexpectedly pressed on with quiz: 'Who wrote Missa Fortuna desperata?' (7,3,4) |
| PLUTO | It has only one-sixth of the mass of Earth's moon |
