William F.Theobald (1994) suggested that "etymologically, the word tour is derived from the Latin, 'tornare' and the Greek, 'tornos', meaning 'a lathe or circle; the movement around a central point or axis'. This meaning changed in modern English to represent 'one's turn'. The suffix –ism is defined as 'an action or process; typical behaviour or quality', while the suffix, –ist denotes 'one that performs a given action'. When the word tour and the suffixes –ism and –ist are combined, they suggest the action of movement around a circle. One can argue that a circle represents a starting point, which ultimately returns back to its beginning. Therefore, like a circle, a tour represents a journey in that it is a round-trip, i.e., the act of leaving and then returning to the original starting point, and therefore, one who takes such a journey can be called a tourist."
Today, three schools discuss on the roots of tourism. The French School, led by A. Houlot argued that the term tourism comes from the old Aramaic Tur, which was used for the trip, exploration and movement of people in the Bible. This word had been used, for the first time, when Moses begins his expedition to the lands of Canaán. Nevertheless, another school of thought - the Onomastic School - considers the origin of the concept not from a linguistic perspective but rather links it to the last name of the French aristocracy Della Tour. According to this school, after Carlos V signs a treaty with England in 1516, in celebration of this event, the future king gives the Della Tour family exclusive rights to conduct commercial transport and related businesses. Last but not least, a third school focuses on the Anglo-Saxon world, situating the Theobald´s development under the lens of scrutiny. Surmising that the roots of the word tourism comes from the Ancient Anglo-Saxon term Torn, these scholars found evidence to think the term was coined in XIIth century which by farmers to denote those travels with intentions to return. Over centuries, the meaning of the word has been shifted to be politically adopted. By the middle of the 18th century, the English noblemen used the term “turn” to refer to the trips undertaken for education, search and culture exploration. In reality, the purpose of the noblemen’s trip to the different parts of Kingdom was to acquire knowledge that was later useful for governing.
source : wikipedia