The terms this week are all related to types of horses used in the medieval period.
(Prestwich, Michael. Armies and Warfare in the Middle Ages: The English Experience, 347)
Palefridus or Palfrey:
The finest sort of riding horse, as opposed to a warhorse. The word is derived from paraveredus, but like caballus it has gone up in the world.
(Davis, R.H.C. The Medieval Warhorse: Origin, Development and Redevelopment, 137)
Catzurius or Cursarius or Courser:
A cursarius or courser: a swift riding horse; occurs in England mainly from the fourteenth century onwards. Possibly a variant of catzurius. Catzurius: A hunter, or horse for the chase; used in England from the end of the twelfth century.
(Davis, R.H.C. The Medieval Warhorse: Origin, Development and Redevelopment, 135)