High Ground is a trait in Destiny 2 that can appear on 43 weapons. There is also an enhanced version with a stronger effect.
What High Ground does
Final blows with this weapon grant stacks of bonus damage. Attacking targets from higher ground immediately grants the maximum number of stacks.
Enhanced version
Final blows with this weapon grant stacks of bonus damage. Attacking targets from higher ground immediately grants the maximum number of stacks. Increases reload.