Óin

Óin was the older brother of Glóin, paternal uncle of Gimli, and the brother in law of Glóin's wife. During TA 2941, Óin acted as the healer to Thorin's Company. He was one of the few dwarves to stay in Laketown to care for a wounded and very sick Kili. They rejoined their friends after the destruction of Laketown and before the Battle of the Five Armies. Bilbo tried to force them to leave before it was too late. Óin was on of the few survivors of the Battle of Five Armies and say on last goodbye to their burglar and friend.

Official description
"Along with his brother Gloin, Oin is a distant cousin of Thorin Oakenshield. A brave Northern Dwarf, Oin joins The Company of Thorin Oakenshield out of a sense of loyalty to his kin, and also because he has a substantial sum of money invested in the venture. Well read with an enquiring mind, Oin is the healer among the Company, often applying an herbal salve of his own invention – which has since come to be known as ‘ointment’ after its maker."

—Warner Bros