1.  rapscallion(n = noun.person) knave, rascal, rogue, scalawag, scallywag, varlet - a deceitful and unreliable scoundrel;
is a kind of scoundrel, villain

2.  rapscallion(n = noun.person) imp, monkey, rascal, scalawag, scallywag, scamp - one who is playfully mischievous;
is a kind of child, fry, kid, minor, nestling, nipper, shaver, small fry, tiddler, tike, tyke, youngster
has particulars: brat, holy terror, little terror, terror

   A rascal; a good-for-nothing fellow. Howitt. [1913 Webster]

rapscallion, n. archaic or joc. a rascal, scamp, or rogue.

Etymology:
earlier rascallion, perh. f. RASCAL

N  bad man, wrongdoer, worker of iniquity, evildoer, sinner, the wicked, bad example, villain, rascal, scoundrel, miscreant, budmash, caitiff, wretch, reptile, viper, serpent, cockatrice, basilisk, urchin, tiger, monster, devil, devil incarnate, demon in human shape, Nana Sahib, hellhound, hellcat, rakehell, bad woman, jade, Jezebel, scamp, scapegrace, rip, runagate, ne'er-do-well, reprobate, scalawag, scallawag, rou_e, rake, Sadist, skeesicks, skeezix, limb, one who has sold himself to the devil, fallen angel, ame damnee, vaurien, mauvais sujet, loose fish, sad dog, rounder, lost sheep, black sheep, castaway, recreant, defaulter, prodigal, rough, rowdy, hooligan, tough, ugly customer, mean mother, ruffian, bully, meanie, Jonathan Wild, hangman, incendiary, arsonist, fire bug, thief, murderer, terrorist, culprit, delinquent, crook, hoodlum, hood, criminal, thug, malefactor, offender, perpetrator, perp, disorderly person, misdemeanant, outlaw, scofflaw, vandal, felon, (convicted criminal), criminal, convict, prisoner, inmate, jail bird, ticket of leave man, multiple offender, blackguard, polisson, loafer, sneak, rapscallion, rascallion, cullion, mean wretch, varlet, kern, ame-de-boue, drole, cur, dog, hound, whelp, mongrel, lown, loon, runnion, outcast, vagabond, rogue, ronian, scum of the earth, riffraff, Arcades ambo, Int, sirrah!, Acherontis pabulum, gibier de potence.