If you're looking to defend yourself against a melee attacking Predator then you're going to really want to know how to parry against them! This will give you time to recover and also give your Fireteam the ability to get free access to assaulting the Predator for a brief period.
Predator: Hunting Grounds How to Parry
To parry the Predator in the game you need to press the melee button right as the Predator is swinging an attack at you. When you're close to the Predator, you will very briefly see a button prompt on the screen for Parry. This window is incredibly short, so rather than relying on that prompt, you're going to want to try and hit the melee button just before you think the parry option is about to come on the screen.
You can watch the following video as an example of how to pull the parry off:
If you're able to time it correctly, you will hear a metal sounds of the Predator's claws and your knife coming together. The Predator will then be briefly stunned and you will not take damage from the melee attack. If you're Fireteam is on the ball, you can really dish out some damage during this time. Utilizing this skill will protect you quite a bit, and will punish any Predator players who just spam melee attacks!
As the Predator, make sure not to get caught being too predictable with your melee strikes. Try to bait their parry if possible, or just only use melee when you can sneak up on someone without them being aware. If you do get parried, you will likely want to immediately flee, because you will be vulnerable to quite a bit of gunfire at that point!