Vantaa.

Originally the name of the river (Vantaanjoki). According to the traditional and still most accepted theory, the name Vantaa originates (through the genitive forms *Vantaan < *Vanantaan) as a reduced form of earlier *Vanantaka, which is related to the name of a village Vanaantaka. Both are from *Vanajantaka, meaning "behind [south of] Vanaja (Vanajavesi)", as named by the Tavastians. According to Saulo Kepsu, the name may have originally been given as *Vanantaanjärvi to a lake now called Erkylänjärvi (the source of the river Vantaa). Viljo Nissilä on the other hand contends that the name was originally given to the village, with Vanaja referring to the entire long watercourse spanning from Janakkala to Tyrväntö. Heikkilä (2014) presents an alternative etymology for the name, tracing it from a Sami term meaning something like “portage” (akin to Proto-Samic *vāncētēk (“to walk; to cross a river”)), referring to the abundant rapids in the river preventing navigation both up and down the river. The original form of the name would have been *Vantas(joki), from which Vantaa by levelling the oblique stem Vanta(h)a-. The city was named after the river which runs through it. The name was officially adopted in 1972, prior to which the municipality had been called Helsingin maalaiskunta (“rural municipality of Helsinki”). The name Vantaa, in reference to the river, is first attested as Vanta in 1613.