au·​to·​collimator | \ " +\
plural -s

Definition of autocollimator

: a telescope with eyepiece adapted to the method of autocollimation either to collimate the instrument itself or to ensure that its axis is perpendicular to a reflecting surface

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First Known Use of autocollimator

1903, in the meaning defined above

History and Etymology for autocollimator

aut- + collimator

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The first known use of autocollimator was in 1903

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to express emotion in a dramatic way

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