[′gal·ē·əm ′ärs·ən‚īd ′fēld i¦fekt tran′zis·tər] (electronics) A field-effect transistor in which current between the ohmic source and drain contacts is carried by free electrons in a channel consisting of n-type gallium arsenide, and this current is modulated by a Schottky-barrier rectifying contact called the gate that varies the cross-sectional area of the channel. Abbreviated GaAs FET.