A very popular name, of uncertain derivation. Until the 20th century it was confined mainly to Scotland and Ireland. It is probably of Scandinavian rather than Celtic origin, however: a short form of any of the various compound names derived from Old Norse brand ‘sword’. Its popularity in Gaelic-speaking countries has no doubt been influenced by its similarity to Brendan.
German: 1. (also Dürst): nickname from Middle High German turst ‘boldness’. 2. from Middle High German durst ‘thirst’, applied as nickname, probably for a heavy drinker; or a habitational name from a farmstead in the Tyrol named with the same word, probably indicating a dry location.