I'm confused with the meaning of "circumvent"
According to my vocabulary book, the meaning of circumvent is "to frustrate as though by surrounding" An example sentence given was, "Our hopes for an early end of the meeting were circumvented by the chairperson's refusal to deal with the items on the agenda."
However, another dictionary says the exact opposite, and said the meaning of CIRCUMVENT is "find a way around (an obstacle)". An example sentence given was, "the checkpoints were easy to circumvent".
So which is it? I'm really confused since I see how these two meanings can be used in the same situation with completely different meanings.