Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun rear_of_tube
1 sense of rear of tube
Sense 1
breech, rear of barrel, rear of tube -- (opening in the rear of the barrel of a gun where bullets can be loaded)
=> opening -- (a vacant or unobstructed space that is man-made; "they left a small opening for the cat at the bottom of the door")