The Collaborative International Dictionary of English v.0.48:

Staircase \Stair"case`\ (st[^a]r"k[=a]s`), n.
   A flight of stairs with their supporting framework, casing,
   balusters, etc.
   [1913 Webster]

         To make a complete staircase is a curious piece of
         architecture.                            --Sir H.
                                                  Wotton.
   [1913 Webster]

   Staircase shell. (Zool.)
   (a) Any scalaria, or wentletrap.
   (b) Any species of Solarium, or perspective shell.
       [1913 Webster]

WordNet (r) 3.0 (2006):

staircase
    n 1: a way of access (upward and downward) consisting of a set
         of steps [syn: stairway, staircase]

The Free On-line Dictionary of Computing (30 December 2018):

jaggies
staircase
staircasing

    /jag'eez/ (Or "staircase") The "staircase" effect
   observable when an edge (especially a linear edge of very
   shallow or steep slope) is rendered on a bitmap display (as
   opposed to a vector display).  The effect is even more
   pronounced when a bitmap image or text in a bitmap font is
   enlarged.  Outline fonts and anti-aliasing are two
   techniques used to solve this problem with text.

   [Jargon File]

   (1997-12-01)