trom·bone 
(trŏm-bōn, trəm-, trŏmbōn′)
(trŏm-bōn, trəm-, trŏmbōn′)n. pl. trom·bones
A brass instrument consisting of a long cylindrical tube bent upon itself twice, ending in a bell-shaped mouth, and having a movable U-shaped slide for producing different pitches.
[Italian , augmentative of tromba, trumpet, probably ultimately of Germanic origin; akin to Old High German trumba; see TRUMPET.]
trom·bonist n.
trombone