This is another entirely irrelevant entry in Cassidy’s book. Yes, we know that Ireland was hit by a terrible famine in the 1840s and that the follies of landlordism and the incompetence and malice of the British authorities were largely responsible for the high level of mortality. We also know that the famine drove large numbers of people from Irish-speaking areas to the States and other countries in search of a better life. But why is this Irish phrase (meaning The Great Famine) an entry in a book on Irish influence on American slang? Did anyone ever talk about the Gortamore in English? If so, Cassidy doesn’t mention it.
In fact, while An Gorta Mór is commonly used in books, I have friends who dislike the term in Irish and won’t use it because they regard it as Béarlachas (an Irish expression which has been influenced by English and sounds foreign). They prefer the term which native Irish speakers tend to use when referring to that dark period of Irish history, an Drochshaol (= the bad life).