Words used by Tennyson to show the fate of the brigade are:
valley of Death
Step-by-step explanation:
The poem "The Charge of the Light Brigade." is about a small brigade of barely 600 men who fight a battle in impossible matter of chance and know that they might be putting up their last stand on the fight. The doom of their situation is thus conveyed masterfully by Tennyson here in this rhyme of valor and pride.
It is in these words where the site of the battle is called the valley of death that we learn what the fate of the persons fighting is going to be and thus this is the phrase that signals their doom.