The term 'BEGIN HOSTILITIES' is a phrase used to describe the start of a WAR. The three crossword solutions for this term are WAR (3 letters), THAW (4 letters), and GOTOWAR (7 letters). WAR is a term used to describe a large-scale armed conflict between two or more nations, while THAW is a term used to describe the process of gradually warming up a frozen area. GOTOWAR is a term used to describe the preparation for a WAR, such as the mobilization of troops and resources.