/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.