Spundzevičius

Perhaps the dialect from *Spandzevičius, whose root spand- could be from lit. spándyti „statyti spąstus, kilpas, žabangas; spaudyti, gniaužyti, mankyti; kamuoti, varginti, tampyti, stumdyti, spardyti and others“ (LKŽ XIII 318) or similar. But a development is also possible from Pundzẽvičius (see) or something like thimm.