To the death is a phrase that means until the very end, often implying a willingness to fight or sacrifice everything. There are many synonyms that could be used to convey this idea, such as "to the bitter end," "fighting to the last breath," "to the point of exhaustion," or "fighting to the death." Other possible synonyms could include "with all one's might," "with unyielding determination," or "with total commitment." Whether used in a physical battle or in a metaphorical sense, these phrases can help convey the sense of a fierce fight, where nothing is held back and everything is put on the line.