GNU Dico
From Jargon File (4.3.1, 29 Jun 2001):
magic 1. adj. As yet unexplained, or too complicated to explain;
compare automagically and (Arthur C.) Clarke's Third Law: "Any
sufficiently advanced technology is indistinguishable from magic." "TTY
echoing is controlled by a large number of magic bits." "This routine
magically computes the parity of an 8-bit byte in three instructions."
2. adj. Characteristic of something that works although no one really
understands why (this is especially called black magic). 3. n.
[Stanford] A feature not generally publicized that allows something
otherwise impossible, or a feature formerly in that category but now
unveiled. 4. n. The ultimate goal of all engineering & development,
elegance in the extreme; from the first corollary to Clarke's Third Law:
"Any technology distinguishable from magic is insufficiently advanced".
Parodies playing on these senses of the term abound; some have made
their way into serious documentation, as when a MAGIC directive was
described in the Control Card Reference for GCOS c.1978. For more about
hackish `magic', see Appendix A. Compare black magic, wizardly,
deep magic, heavy wizardry.