In a Sherlock Holmes story, Holmes asks Watson to define
"I suppose, Watson, we must look upon you as a man of letters," said he. "How do you define the word 'grotesque'?"

"Strange--remarkable," I suggested.

He shook his head at my definition.

"There is surely something more than that," said he; "some underlying suggestion of the tragic and the terrible."

grotesque (from AHD)

ADJECTIVE: 1. Characterized by ludicrous or incongruous distortion, as of appearance or manner. 2. Outlandish or bizarre, as in character or appearance. See synonyms at fantastic. 3. Of, relating to, or being the grotesque style in art or a work executed in this style.
NOUN: 1. One that is grotesque. 2a. A style of painting, sculpture, and ornamentation in which natural forms and monstrous figures are intertwined in bizarre or fanciful combinations. b. A work of art executed in this style.
ETYMOLOGY: From French, a fanciful style of decorative art, from Italian grottesca, from feminine of grottesco, of a grotto, from grotta, grotto. See grotto.
OTHER FORMS: gro·tesquely —ADVERB