"like a dried herring"
Wordplay
Act 2,
Scene 4
Lines 35-36
Mercutio
Mercutio jokes that Romeo has turned from flesh into fish — a dried herring to be exact. Herring was sold in the markets of Shakespeare’s London. Typically it was dried after the roe, the eggs, were removed. But the term “roe” also referred to the male sperm of the fish, and that’s how Mercutio’s using it when he describes Ro-meo as roe-less (after presumably having spent the night with Rosaline).