collimator

Từ điển Oxford Learners Wordfinder Dictionary

noun

1. a small telescope attached to a large telescope to use in setting the line of the larger one
• Derivationally related forms:
collimate
• Hypernyms:
telescope, scope
2. optical device consisting of a tube containing a convex achromatic lens at one end and a slit at the other with the slit at the focus of the lens;
light rays leave the slit as a parallel beam
• Hypernyms:
optical device
• Part Holonyms:
spectroscope, prism spectroscope