† betasObs.rare—1. [a. ON.beiti-áss sailyard, ? f.beita to make the ship catch the wind, to tack + áss pole, yard; cf.windlass, in ME.windas, in ON.vindáss.] A sailyard. c1330R. Brunne in Layamon III. 396 Som aforced the wyndas, Som the lofe, som the betas.