Source Core Rulebook pg. 283
An unarmed attack uses your body rather than a manufactured weapon. An unarmed attack isn’t a weapon, though it’s categorized with weapons for weapon groups, and it might have weapon traits. Since it’s part of your body, an unarmed attack can’t be Disarmed. It also doesn’t take up a hand, though a fist or other grasping appendage follows the same rules as a free-hand weapon.

Monk Unarmed Attacks

Crane Wing, Dragon Tail, Falling Stone, Fire Talon, Iron Sweep, Lashing Branch, Tiger Claw, Wind Crash, Wolf Jaw