Definition of "undraw"

undraw

verb
third-person singular simple present undraws, present participle undrawing, simple past undrew, past participle undrawn
1. (transitive) To draw aside or open; to pull back a layer of fabric, e.g. a curtain.
2. (transitive) To clear or erase part of a drawing.
  Quotations
  It is easy to highlight graphics on a monochrome system. The simplest way is to set the GC to the GXxor logical function and draw your graphics once to draw them and again to undraw them.
  1992, Adrian Nye, XLIB Programming Manual, Rel. 5, page 205