quar·to 
(kwôrtō)
(kwôrtō)n. pl. quar·tos
1. The page size obtained by folding a whole sheet into four leaves.
2. A book composed of pages of this size.
[Short for Middle English (in) quarto, (in) the fourth part (of a sheet), from Medieval Latin (in) quārtō, from Latin, ablative of quārtus, fourth; see kwetwer- in the Appendix of Indo-European roots.]
- concrete
- concretely
- concrete music
- concreteness
- concrete poetry
- concretion
- concretionary
- concretism
- concretist
- concretization
- concretize
- concubinage
- concubine
- concupiscence
- concupiscent
- concupiscible
- concur
- concurrence
- concurrency
- concurrent
- concurrently
- concurrent resolution
- concuss
- concussion
- concussive