There are several synonyms for the phrase "become exhausted," each with slight variations in meaning. "Tire out" suggests that a person has become fatigued from physical activity, such as exercise or labor. "Collapse" implies a sudden and complete loss of energy or strength. "Burn out" conveys a feeling of emotional exhaustion, often resulting from prolonged stress or overwork. "Wear down" emphasizes the gradual draining of energy or stamina over time. "Deplete" suggests a depletion of resources, such as energy or strength. Other similar phrases include "run down," "run out of steam," "drain," and "sapped".