Laudator Temporis Acti

J. Huizinga, The Waning of the Middle Ages (1949; rpt. Garden City: Doubleday Anchor Books, 1954), p. 144:

At the close of the Middle Ages the whole vision of death may be summed up in the word macabre, in the modern meaning. Of course, this meaning is the outcome of a long process. But the sentiment it embodies, of something gruesome and dismal, is precisely the conception of death which arose during the last centuries of the Middle Ages. This bizarre word appeared in French in the fourteenth century, under the form macabré, and, whaever may be its etymology, as a proper name. A line of the poet Jean Le Fèvre, "Je fis de Macabré la dance," which may be dated 1376, remains the birth-certificate of the word.

The Concise Oxford Dictionary of English Etymology:

macabre in Dance Macabre, the Dance of Death XV (daunce of machabree); (from modF.) gruesome XIX. The form now usual repr. F. macabre (XIX), error for OF. macabré, perh. alt. of OF. Macabé Maccabee; the orig. ref. may have been to a miracle play containing the slaughter of the Maccabees.

There is much useful information on the etymology of macabre at Le Trésor de la Langue Française Informatisé and Centre National de Ressources Textuelles et Lexicales. The French are lucky; I'm not aware of comparably rich sources of information on English etymology available on the Internet for free. But Anatoly Liberman, Macabre, gully & gulch, is available for free and contains a good summary. Liberman considers the following possible etymologies:

• From Arabic maqbara (tomb) or Biblical Hebrew/Aramaic m(e)qaber (grave digger)
  
• From Saint Macarius, the Egyptian hermit
  
• From a proper name Macabre (a painter or poet who may have depicted the dance of death)
  
• From the Biblical name Macchabaeus

Liberman regards Macchabaeus as "the best candidate." He further states, "To answer the question about macabre, I have read more than a dozen articles in English, French, and German and as many chapters in books on the dance of death." Unfortunately, he doesn't list the articles or books. Here are a few references (most of which I haven't seen):

• Gaston Paris, "La Dance Macabre de Jean Le Fèvre," Romania 24 (1895) 129-132
  
• Robert Eisler, "Danse Macabre," Traditio 6 (1948) 187-225
  
• James M. Clark, "The Etymology of Macabre: A Recent Theory," Archivum Linguisticum 1 (1949) 140-?
  
• Leo Spitzer, "La danse macabre," in Mélanges de linguistique offerts à Albert Dauzat par ses élèves et ses amis (Paris: Artrey, 1951), pp. 307-321
  
• Edelgard E. DuBruck, "Another look at macabre," Romania 79 (1958) 536-544
  
• Hans Sperber, "The Etymology of Macabre," in Studia Philologica et Litteraria in Honorem Leo Spitzer (Bern: Francke, 1958), pp. 391-401
  
• Armand Machabey, "À propos de la discussion sur la Danse Macabre," Romania 80 (1959) 118-129
  

Given the derivation from Macchabaeus, Armand Machabey could be considered an aptronymn.

From Hans Holbein, Totentanz