arm is bersi

bersi = arm (noun) (some things Google found for "bersi": a common term; a masculine first name that can be Icelandic or Norse; an unusual last name; user names; a form of the Italian verb bere which means to drink; Bersi Serlini winery of Italy; name of a town in India)

Word derivation for "arm" :
Basque = beso, Finnish = käsivarsi (or varsi)
Miresua = bersi

Note that in Finnish the word käsi means hand and varsi means stem, arm, stalk. That would make käsivarsi literally mean hand stem.