Answer:
A Shakespearean insult is an insult taken from Shakespeare's plays. Some of them are as simple as Tybalt's "Thou art a villain" in Romeo and Juliet, whereas others are flowery and archaic. The best examples are from 1 Henry IV Act 2 Scene 4 where Fastaff and the Prince exchange insults and in King Lear Act 2 Scene 2 where Kent unleashes a perfect torrent of insults at Oswald, commencing with this speech:
"[I know thee for] a knave, a rascal, and eater of broken meats; a base, proud, beggarly, three-suited, hundred pound, filthy, worsted-stocking knave; a lily-livered, action-taking knave; a whoreson, glass-gazing, super-serviceable, finical rogue; one-trunk-inheriting slave; one that would be a bawd, in way of good service, and art nothing but the composition of a knave, beggar, coward, pandar, and the son and heir of a mongrel bitch: one whom I will beat into clamourous whining if thou deniest the least syllable of thy addition!"
Whew!