Source : Webster's Revised Unabridged Dictionary (1913)

Madcap \Mad"cap`\, a.
   1. Inclined to wild sports; delighting in rash, absurd, or
      dangerous amusements. ``The merry madcap lord.'' --Shak.

   2. Wild; reckless. ``Madcap follies'' --Beau. & Fl.

Madcap \Mad"cap`\, n.
   A person of wild behavior; an excitable, rash, violent
   person. --Shak.

Source : WordNet®

madcap
     adj : characterized by undue haste and lack of thought or
           deliberation; "a hotheaded decision"; "liable to such
           impulsive acts as hugging strangers"; "an impetuous
           display of spending and gambling"; "madcap escapades";
           (`brainish' is archaic) [syn: {hotheaded}, {impulsive},
            {impetuous}, {tearaway(a)}, {brainish}]
     n : a reckless impetuous irresponsible person [syn: {daredevil},
          {hothead}, {swashbuckler}, {lunatic}, {harum-scarum}]

Source : Free On-Line Dictionary of Computing

MADCAP
     
        Math and set problems, for the Maniac II and CDC 6600.
        "MADCAP - A Scientific Compiler for a Displayed Formula
        Texbook Language", M.B.  Wells, CACM 4(1):31-36 (Jan 1961).
        Sammet 1969, pp.271-281.  Versions: Madcap 5 (1964), Madcap 6.
        "The Unified Data Structure Capability in Madcap 6",
        M.B. Wells et al, Intl J Comp Info Sci 1(3) (sep 1972).