Answer: telescoping

AnswerCrossword Clue
telescopingBe capable of sliding together in this way
telescopingTELESCOPE
telescopingCause (an object made of concentric tubular parts) to slide into itself, so that it becomes smaller
telescopingCondense or conflate so as to occupy less space or time
telescopingCrush (a vehicle) by the force of an impact