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general::
Phrase(s): ride herd on someone or something
Fig. to supervise someone or something. (Alludes to a cowboy supervising cattle.) • I’m tired of having to ride herd on my kids all the time. • My job is to ride herd on this project and make sure everything is done right.
McGrawhill's American Idioms And Phrasal Verbs
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Keep close watch or tight control over, as in Aunt Martha is always riding herd on her bridge club, making sure they follow the rules. This idiom alludes to the cowboy who rides around a herd of cattle to keep them together. [Late 1800s]
American Heritage Idioms