Early 19th century: earlier form of toffee, ultimate origin unknown.

• toff from mid 19th century:

  This is perhaps an alteration of tuft, once a term for titled undergraduates at Oxford and Cambridge, who wore a gold tassel on their caps—social climbers and toadies were called tuft-hunters from the mid 18th century. The associations of the word may have influenced toffee-nosed or ‘snobbish’, which was originally military slang. Toffee seems to have been a desirable commodity to soldiers during the First World War— not be able to do something for toffee, or be totally incompetent at it, is first recorded in 1914 in the mouth of a British ‘Tommy’. Toffee (early 19th century) is an alteration of taffy (early 19th century), now mainly used in North America for a sweet resembling toffee. The Taffy that is a name for a Welshman is quite different, representing a supposed Welsh pronunciation of the name David or Dafydd.

Mid 17th century: representing a supposed Welsh pronunciation of the given name Davy or David (Welsh Dafydd).