The Mermaid's Kiss is a ship.
After the passing of Lord Corlys Velaryon in King's Landing, his body was sailed from the capital to Driftmark aboard the Mermaid's Kiss by Marilda of Hull and her surviving son, Alyn Velaryon, Corlys's designated heir. Corlys's body was then buried at sea aboard the Sea Snake near Dragonstone.
A Dance with Dragons
On the first day of their stay in Volantis, Prince Quentyn Martell, Ser Gerris Drinkwater, and Ser Archibald Yronwood seek passage on the Mermaid's Kiss to sail to Queen Daenerys Targaryen in Meereen. The captain refuses them, however. It is unknown if this is the same ship once sailed by Marilda of Hull.