(lemmings)
1.
A lemming is an animal that looks like a large rat with thick fur. Lemmings live in cold northern regions and sometimes travel in very large numbers.
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2.
If you say that a large group of people are acting like lemmings, you are critical of them because they all follow each other into an action without thinking about it.
The French crowds pour like lemmings down the motorway to Paris.
N-COUNT: usu pl [disapproval]