lemmings

Noun

lemming (plural lemmings)

1. A small arctic and subarctic rodent of the tribes Lemmini, Dicrostonychini and Lagurini.
   • The well-known lemmings, in severe winters, at long intervals, move down from the mountains of Scandinavia in immense numbers, crossing lakes and rivers, eating their way through haystacks, and surmounting every obstacle till they reach the sea, whence very few return.1876, Alfred Russel Wallace, The Geographical Distribution of Animals, chapter 2, page 18
2. (figuratively) Any member of a group given to conformity or groupthink, especially a group poised to follow a leader off a cliff.
   • Lemmings are strongly cohesive, but could be, in organisational terms, highly destructive for the business.2004, Ilse Hobbs, Jan Havenga, A Practical Guide to Strategy, →ISBN, page 127