严峻 (yánjùn) describes a situation, challenge, or expression that is severe, stern, and grim — often used for tests, looks, or circumstances that feel harsh and forbidding. It is stronger and more solemn than 严重 (yánzhòng 'serious, grave'), which focuses on the gravity of a problem or illness, and unlike 严厉 (yánlì 'strict, severe'), which describes a person's manner or punishment, 严峻 typically modifies abstract nouns like 考验 (test) or 挑战 (challenge).