What does 1 Chronicles 12:8 mean?

Some of the warriors from Gad also joined David at his stronghold in the wilderness. They were brave fighters, trained for battle, able to handle shield and spear. They looked fierce, like lions, and were as quick as gazelles on the hills. 1 Chronicles 12:8 - Modern Text Bible

(This verse describes the impressive skills and appearance of the Gadite warriors who joined David, emphasizing their courage and speed.)