Knockback
Knockback is a stat on gear: how far your hits push enemies back.
Sources
- Appears as a base stat on 28 pieces of gear (2 accessories, 21 armor, 5 weapons).
- Can roll as a dungeon bonus stat on 93 items — see each item's Possible rolls section.
Notable items: 
Cursed Celestial Sword · Foundation Bulwark Helm · 
Celestial Blast Pendant · 
Foundation Bulwark Chestguard · Foundation Bulwark Greaves · 
Celestial Hammer
Affinity rolls
Knockback can also roll bound to a single ability (on gear and relics) instead of applying globally — see Ability Affinity Stats.