To beg someone earnestly or desperately to do something.
It implies a strong sense of urgency and pleading.
Here are some examples:
* She entreated him to stay. (She begged him strongly to stay.)
* The child entreated her parents for a puppy. (The child begged her parents very sincerely for a puppy.)
* He entreated his friends for help. (He desperately asked his friends to help him.)
"Entreat" can also be used as a noun, meaning a plea or earnest request.
Let me know if you'd like more examples or have any other questions!