/glas T-T-Y/ or /glas ti'tee/ A terminal that has a display
screen but which, because of hardware or software limitations,
behaves like a teletype or some other printing terminal,
thereby combining the disadvantages of both: like a printing
terminal, it can't do fancy display hacks, and like a display
terminal, it doesn't produce hard copy. An example is the
early "dumb" version of Lear-Siegler ADM 3 (without cursor
story about a glass tty.