The word "急切" is a compound formed by combining two synonymous characters, "急" (jí), meaning "urgent" or "anxious," and "切" (qiè), meaning "eager" or "keen." This structure follows a common pattern in Chinese morphology where two characters with similar or related meanings are joined to create a single, more emphatic concept. The resulting word, "急切," conveys a strong sense of urgency and eager impatience, where the meaning of the whole is reinforced and nuanced by the combination of its parts.