Source : Webster's Revised Unabridged Dictionary (1913)

Picaresque \Pic`a*resque"\, a. [F., fr. Sp. picaro rogue.]
   Applied to that class of literature in which the principal
   personage is the Spanish picaro, meaning a rascal, a knave, a
   rogue, an adventurer.

Source : WordNet®

picaresque
     adj : involving clever rogues or adventurers especially as in a
           type of fiction; "picaresque novels"; "waifs of the
           picaresque tradition"; "a picaresque hero"