GMST Class Testing

From the Adventurers skill thread:

Phoenix
Description Temporarily summons Phoenix to deal Fire damage to up to 4 monsters. Has a chance to Knock-down enemies. \nRequired skill: #cSilver Hawk Lv. 15#

1	MP Cost: 40, Summon Duration: 104 sec, Damage: 215%, Max Monsters Hit: 4, Knock-down Chance: 37%
30	MP Cost: 100, Summon Duration: 220 sec, Damage: 360%, Max Monsters Hit: 4, Knock-down Chance: 95%

What is this knockdown effect? Is it the same as knockback? That could be quite annoying when it knockbacks a monster out of your range.

I tried to look at videos, but I could only find BMs bossing while Phoenix just did damage.