telescope

An arrangement of lenses or mirrors or both that gathers 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, absorption, or reflection of electromagnetic 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.