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drawtube

American  
[draw-toob, -tyoob] / ˈdrɔˌtub, -ˌtyub /

noun

  1. a tube sliding within another tube, as the tube carrying the eyepiece in a microscope.


drawtube British  
/ ˈdrɔːˌtjuːb /

noun

  1. a tube, such as one of the component tubes of a telescope, fitting coaxially within another tube through which it can slide

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of drawtube

First recorded in 1890–95; draw + tube