An optical instrument used in viewing distant objects, as the heavenly bodies.
- An arrangement of lenses or mirrors or both that gathers visible light, permitting direct observation or photographic recording of distant objects.
- Any of various devices, such as a radio telescope, used to detect and observe distant objects by their emission, transmission, reflection, or other interaction with invisible radiation.
- To cause to slide inward or outward in overlapping sections, as the cylindrical sections of a small hand telescope do.
- To make more compact or concise; condense.
- To slide inward or outward in or as if in overlapping cylindrical sections: a camp bucket that telescopes into a disk.