From LSWiki

Class: Combat Skills
Attribute: Dexterity
Pedagogy: Physical Training

The ability to use your natural weaponry -- fists, claws, fangs, horns, and 
so on -- in combat, as well as various weapons that are used in a similar way, 
such as knuckle-dusters and artificial claws.  When fighting in this manner, 
your unarmed skill influences your ability to hit your opponent, the damage 
you inflict, how fast your attacks are, and how well you can block attacks.

Trainers

Wandering Lhethan Hagal, Wikspisk
Avalon: Bercilak
Hanoma: Olaris Wanders
Kolond: Duthien (only trains dwarves)
Losthaven: Raelan Jax
Mycenae: Kyros
Shatterspire: Sthlar
Skarlan: Badlokk
Sseraka: Sscantha
Stillwater: Captain Roberts
Yathryn: Kajax (worship requirement)
Xi Feng Ming: Shun Lang
Association required:
Maidens of the Spear:  Sulin
Guild required:
Aisenshi: Musashi
Brute Squad: Fezzik
Ordo Ignis Aeternis: Aedryl 
Ordo Ignis Aeternis: Iklam wanders
Knights of the Round Table: Sir Lancelot
Reapers: Holton Jax
Shapeshifters Maramar
Quest required:
Corna Quests: Marshall Osaka