quaternary /kwə- or kwo-tûrˈnə-ri/

1. Consisting of four
2. By fours
3. In fours
4. Of the fourth order
5. Based on four
6. With four variables
7. (with cap) of or belonging to the most recent period of the Cenozoic era, starting 1.8 million years ago (geology)
8. Connected to four non-hydrogen atoms (chem)

1. The number four
2. A set of four
3. (with cap) the Quaternary period or system (geology)

quaterˈnate adjective

In sets of four

quaterˈnion noun

1. A set or group of four
2. The operation of changing one vector into another, or the quotient of two vectors, depending on four geometrical elements and expressible by an algebraical quadrinomial (mathematics)
3. (in pl) a calculus concerned with this, invented by Sir William Rowan Hamilton (1805–65)

• torches
• torchier
• torchiers
• torching
• torchings
• torchière
• torchières
• torchlight
• torchlights
• torch-lilies
• torch-lily
• torchon
• torchon lace
• torchon paper
• torchons
• torch-race
• torch-races
• torch singer
• torch singers
• torch song
• torch songs
• torch-staff
• torch-staves
• torch-thistle
• torch-thistles