/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 control). See tuBe, tty compare dumB terminal, {smart terminal}. See "{TV Typewriters}" for an interesting true story aBout a glass tty.