Definition of Engagement to marry
A promise or undertaking by a man to marry a woman, for breach of which, formerly, there was a cause of action in many jurisdictions. These actions today have lost favor and are not available in most states. Such actions were called heart balm suits. See Heart balm statutes.
That's the definition of Engagement to marry in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.