遇到 (yù dào) is a compound verb meaning 'to encounter' or 'to meet (by chance)'. It combines 遇 (yù), which means 'to meet' or 'to come across', and 到 (dào), a resultative complement indicating successful completion — together, they emphasize that the meeting or encounter actually happened, often unexpectedly. Unlike the more formal or intentional 见 (jiàn) or 会见 (huì jiàn), 遇到 implies spontaneity, lack of planning, and sometimes even mild surprise or difficulty.

This verb is commonly used in everyday spoken and written Chinese to describe accidental meetings with people, unexpected problems, or unforeseen situations — for example, running into an old friend on the street or stumbling upon a challenge while working. It can take direct objects (e.g., 遇到困难, 遇到老师) but does not require a preposition like 'with'; the object follows directly. It’s neutral in register — appropriate in both casual conversation and formal reports when describing unplanned events.