Source : Webster's Revised Unabridged Dictionary (1913)

Handbook \Hand"book`\, n. [Hand + book; cf. AS. handb[=o]c, or
   G. handbuch.]
   A book of reference, to be carried in the hand; a manual; a
   guidebook.

Source : WordNet®

handbook
     n : a concise reference book providing specific information
         about a subject or location [syn: {enchiridion}, {vade
         mecum}]