Neva.

Probably from neva, but at least definitely related to it. The surname is from place names. According to Heikkilä (2012), the name of the river came first, and the geographical term neva is abstracted from the former. He argues that the name of the river would be borrowed from Pre-Germanic *Newā (< *néweh₂ (“new”), compare Swedish ny, English new), in reference to a 'new' river which only came into existence around 1350–1300 BC due to glacial rebound; Heikkilä also connects Samic words (Northern Sami njavvi) into this etymology by arguing that they were borrowed from Early Proto-Finnic *Nëva. Kallio (2018), however, disputes this, as there does not appear to be any toponymic evidence for Germanic or Indo-European presence in the region prior to the 8th century AD, and the distribution of the Finnic *nëva appears too broad to argue that it could derive from the name of the river; he argues that the name derives from Proto-Finnic *nëva (“fen, swamp”) and originally referred to Lake Ladoga (and was later also applied to the river).