What is the medical term for mouth disease?

Where does the term "foot-in-mouth disease" find its origins?

• Answer:

  The phrase is a play on foot and mouth disease. A rather nasty viral infection which affects sheep and other related animals. You may remember the foot and mouth outbreaks in the UK in 2001 and 2007. The origins of foot in mouth has been attributed to Sir Boyle Roach who was an Irish politician in the eighteenth century. He was famous for using funny malapropisms and was remarked upon as  stating "Half the lies our opponents tell about me are not true". It is said a fellow parliamentarian quipped "Every time he opens his mouth he puts his foot in it!"