The city of Tromsø is named after the island of Tromsøya, on which it stands. The last element of the city's name comes from the word for "island" (, Danish: ø), but the etymology of the first element is uncertain. Several theories exist. One theory holds "Troms-" to derive from the old (uncompounded) name of the island (Old Norse: Trums). Several islands and rivers in Norway have the name Tromsa, and the names of these are probably derived from the word straumr which means "(strong) current". (The original form must then have been Strums, for the missing s see Indo-European s-mobile.) Another theory holds that Tromsøya was originally called Lille Tromsøya (Little Tromsøya), because of its proximity to the much bigger island today called Kvaløya, that according to this theory was earlier called "Store Tromsøya" due to a characteristic mountain known as Tromma (the Drum). The mountain's name in Sami (or Sámi), Rumbbučohkka, is identical in meaning, and it is said to have been a sacred mountain for the Sámi in pre-Christian times.
