The Collaborative International Dictionary of English v.0.48:

Quad \Quad\, Quade \Quade\, a. [Akin to AS. cw[=ae]d, cwead,
   dung, evil, G. kot, dung, OHG. qu[=a]t.]
   Evil; bad; baffling; as, a quade wind. [Obs.]
   [1913 Webster]

         Sooth play, quad play, as the Fleming saith. --Chaucer.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Quad \Quad\, n. (Print.)
   A quadrat.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Quad \Quad\, n. (Arch.)
   A quadrangle; hence, a prison. [Cant or Slang]
   [1913 Webster]

WordNet (r) 3.0 (2006):

quad
    n 1: one of four children born at the same time from the same
         pregnancy [syn: quadruplet, quad]
    2: a muscle of the thigh that extends the leg [syn:
       quadriceps, quadriceps femoris, musculus quadriceps
       femoris, quad]
    3: (printing) a block of type without a raised letter; used for
       spacing between words or sentences [syn: quad, space]
    4: a rectangular area surrounded on all sides by buildings [syn:
       quad, quadrangle]

The Jargon File (version 4.4.7, 29 Dec 2003):

quad
 n.

    1. Two bits; syn. for quarter, crumb, tayste.

    2. A four-pack of anything (compare hex, sense 2).

    3. The rectangle or box glyph used in the APL language for various arcane
    purposes mostly related to I/O. Former Ivy-Leaguers and Oxford types are
    said to associate it with nostalgic memories of dear old University.


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

quad

    The rectangle or box glyph used in the APL
   language for various arcane purposes mostly related to I/O.

   [Jargon File]

   (2007-05-31)