'Ground' in the Bible

Therefore, put on the complete armor of God, so that you will be able to [successfully] resist and stand your ground in the evil day [of danger], and having done everything [that the crisis demands], to stand firm [in your place, fully prepared, immovable, victorious].

So stand firm and hold your ground, having tightened the wide band of truth (personal integrity, moral courage) around your waist and having put on the breastplate of righteousness (an upright heart),