/ma-jik/
adj. 1. 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. Characteristic of something that works although no one really understands why (this is especially called black magic).
3. [Stanford] A feature not generally publicized that allows something otherwise impossible, or a feature formerly in that category but now unveiled.
Compare deep magic, wizardly, heavy wizardry.