Lucasta

I might be mistaken, but this name was Lovelace's pet name for his fiancee, Lucy Sacheverell. He used the name in his poem "To Lucasta, Going To The Wars", written during the Great Civil War in England (1641-1649). When a rumor had leaked that Lovelace was killed, Lucy married another; Lovelace had actually been imprisoned and, hoping to still woo his lady, he wrote poems to her, including "To Lucasta, Going To The Wars".