北爱 is formed by combining the character 北, meaning "north", with 爱, which is the first character of 爱尔兰 (Ireland), to create an abbreviated form representing 北爱尔兰 (Northern Ireland).
Word Definition - 北爱
běi àiabbr. for 北愛爾蘭|北爱尔兰[běi ài ěr lán], Northern Ireland