'Expert in War' in the Bible

Of Zebulun, such as went forth to battle, expert in war, with all instruments of war, fifty thousand, which could keep rank: they were not of double heart.

And of the Danites expert in war twenty and eight thousand and six hundred.

And of Asher, such as went forth to battle, expert in war, forty thousand.

They all hold swords, being expert in war: every man hath his sword upon his thigh because of fear in the night.