pieli + -nen, probably after the peninsula Pielniemi (Pieliniemi), in reference to the long, narrow shape of the peninsula that is located at the side of the river and roughly parallel with it.[1]
^ Sirkka Paikkala, editor (2007), Suomalainen paikannimikirja [Book of Finnish Place names] (in Finnish), Helsinki: Karttakeskus, Kotimaisten kielten tutkimuskeskus, →ISBN