Tired to death is an idiom used to express extreme exhaustion and fatigue. There are many synonyms for this phrase that can be used interchangeably to convey the same feeling. Some of these synonyms include exhausted, drained, weary, fatigued, worn out, shattered, spent, dead to the world, and knackered. All of these words describe the same feeling of being utterly exhausted and in need of rest. Whether you use "tired to death" or one of these similar phrases, the sentiment is clear: you are beyond tired and need some time to recharge.