Source : Webster's Revised Unabridged Dictionary (1913)

Telescopically \Tel`e*scop"ic*al*ly\, adv.
   In a telescopical manner; by or with the telescope.

Source : WordNet®

telescopically
     adv : in a telescopic manner; "each of the four legs contains a
           simple screw jack with a thrust bearing that is
           operated telescopically inside of two tubes"