Laddie is a warm, small word for a boy. Adults say it when they like the boy, or when they want to sound kind: Come here, laddie. You hear it most in Scotland, and in songs and stories that want a Scottish or fond colour. It can stretch to a young man, still said with a smile. It is not the ordinary classroom word — boy or guy will do in Taiwan. It is friendly, not official, and a little old-fashioned outside Scotland.