n. An optical instrument used in viewing distant objects, as the heavenly bodies.verb-intransitive. To slide or pass one within another, after the manner of the sections of a small telescope or spyglass; to come into collision, as railway cars, in such a manner that one runs into another; to become compressed in the manner of a telescope, due to a collision or other force.v. To cause to come into collision, so as to telescope.v. to shorten or abridge significantly.adj. Capable of being extended or compacted, like a telescope, by the sliding of joints or parts one within the other; telescopic