armscye

[ ahrm-sahy, -zahy ]
/ ˈɑrm saɪ, -zaɪ /

noun

the armhole opening in a garment.
Also arms·eye [ahrmz-ahy] /ˈɑrmzˌaɪ/.

Origin of armscye

arm1 + scye armhole (orig. Scottish, Ulster dial. s(e)y, sie, of uncertain origin); reanalyzed by folk etymology as “arm's eye”