Transferred use of the surname, in origin a Norman French occupational name (from traverser ‘to cross’) for someone who collected a toll from users of a bridge or a particular stretch of road. It is now widely used as a given name, especially in the United States.
English: from the Norman personal name Warin, derived from Germanic war(in) ‘guard’, and used as a short form of various compound names with this first element. Compare, for example, Warner 2. The name was popular in France and among the Normans, partly as a result of the popularity of the Carolingian lay Guérin de Montglave.