终于 (zhōngyú) is an adverb meaning 'finally' or 'at long last,' expressing relief, patience, or culmination after a period of waiting, difficulty, or effort. The character 终 (zhōng) means 'end' or 'final,' while 于 (yú) is a classical particle that, in this compound, functions to emphasize completion or attainment. Together, they convey the idea of reaching a long-awaited endpoint — not just chronological finality, but emotional resolution.

This word is commonly used in spoken and written Chinese to highlight contrast between prior struggle/delay and eventual success or change. It often appears with verbs indicating achievement (e.g., 找到, 完成, 到达) or states shifting (e.g., 明白, 决定). Unlike neutral words like 最后 (zuìhòu), 终于 carries strong subjective weight — implying the speaker feels the outcome was hard-won or overdue. It typically appears at the beginning of a clause or before the main verb.