“Do you know Mr. Robert Ferrars?" asked Elinor.

"Not at all—I never saw him; but I fancy he is very unlike his brother—silly and a great coxcomb."

"A great coxcomb!" repeated Miss Steele, whose ear had caught those words by a sudden pause in Marianne’s music.— "Oh, they are talking of their favourite beaux, I dare say.”

"I can answer for it that Miss Dashwood’s is not,’ said Mrs. Jennings, laughing heartily; ‘for he is one of the modestest, prettiest behaved young men I ever saw; but as for Lucy, she is such a sly little creature, there is no finding out who SHE likes.” (Sense and Sensibility, chapter 24, pp. 18–19)

Based on this excerpt, what does the term coxcomb most likely mean?

a man who is absurdly handsome
a man who is deeply admired by society
a foolish and irresponsible man devoted to nothing
a vain and conceited man devoted to style and neatness