Recorded in a number of spellings including Silcock, Silcocks, and Silcox, this is an English surname. It is a patronymic from a medieval short form of the personal name "Silvester", a name of three of the early popes. Silvester, from the Roman (Latin) "Silvestre" meaning "forest dweller", was introduced into England after the Norman Conquest of 1066. It may be a crusader name, that is to say a name of biblical origins, and one which was brought back by the Knight Templars on their return from the Holy Land in the 12th century, or it may be associated with the Christian Revival period of the 12th century and earlier. Either way it developed a number of nickname or short forms of which "Sil" was the most popular. To this has been added various suffix all meaning "son of". Curiously the name originally was found only as a personal name, such an example being Silcokkus of Altringham, Cheshire, in 1283, with William Selecock of Somerset in 1327 being one of the earliest of the surname recordings, and John Silcok of Yorkshire appearing in the Poll Tax registers for that county in 1379.