Source : Webster's Revised Unabridged Dictionary (1913)

Mnemonic \Mne*mon"ic\, Mnemonical \Mne*mon"ic*al\, a. [Gr. ?,
   fr. ? mindful, remembering, ? memory, ? to think on,
   remember; akin to E. mind.]
   Assisting in memory.

Source : WordNet®

mnemonic
     adj : of or relating to or involved the practice of aiding the
           memory; "mnemonic device" [syn: {mnemotechnic}, {mnemotechnical}]

Source : Free On-Line Dictionary of Computing

mnemonic
     
         A word or string which is intended to be easier
        to remember than the thing it stands for.  Most often used in
        "{instruction mnemonic}" which are so called because they are
        easier to remember than the {binary} patterns they stand for.
        Non-printing {ASCII} characters also have mnemonics like
        {NAK}, {ESC}, {DEL} intended to evoke their meaning on certain
        systems.
     
        (1995-05-11)