rat [OE] The rat has been part of our language since Anglo-Saxon times, but its ultimate origin is not known. It probably goes back to the time when the creature first came to Europe from Asia. The term rat race has been used since the mid 20th century. The image behind this is of rats struggling with each other to move forward in a confined space, rather than of the ordered world of a race track. Sailing ships would traditionally have been infested with rats, which would try to escape en masse from a vessel that was in trouble. This gave rise to rats deserting a sinking ship. A person has been a rat since the 1570s, and to rat [E19th] started as ‘to desert a cause, become a traitor’ and then ‘to inform on’. Someone who suspects a trick is said to smell a rat—a phrase which in the 18th century is found as part of an elaborate mixed metaphor attributed to an Irish politician, Boyle Roche: ‘Mr Speaker, I smell a rat; I see him forming in the air and darkening the sky; but I’ll nip him in the bud.’