Dead Pile
From LOTR-TCG Wiki
From the Comprehensive Rules:
Killed Free Peoples characters are placed in your dead pile. The dead pile is separate from and next to your discard pile.
When you have a unique companion or ally in your dead pile, you cannot play another copy of that card, or any other card with the same title. You may play another copy of a non-unique card that is in your dead pile.
When game text instructs you to place a character in the dead pile, that character has been killed.
See also discard, leaving play, The Rule of 9, threats.- Dead Pile section