Real Dictionary

telescope
countable noun: A telescope is a long instrument shaped like a tube. It has lenses inside it that make distant things seem larger and nearer when you look through it.

telescope in American English
an optical instrument for making distant objects, as the stars, appear nearer and consequently larger: it consists of two or more lenses or mirrors
having parts that slide one inside another
to cause to telescope
to slide or be forced one into another like the concentric tubes of a small, collapsible telescope
adjective: consisting of parts that fit and slide one within another
intransitive verb: to slide together, or into something else, in the manner of the tubes of a jointed telescope
noun: an optical instrument for making distant objects appear larger and therefore nearer. One of the two principal forms (refracting telescope) consists essentially of an objective lens set into one end of a tube and an adjustable eyepiece or combination of le
transitive verb: to force together, one into another, or force into something else, in the manner of the sliding tubes of a jointed telescope

telescope in British English
noun: an optical instrument for making distant objects appear larger and brighter by use of a combination of lenses (refracting telescope) or lenses and curved mirrors (reflecting telescope)
verb: to crush together or be crushed together, as in a collision