trombone

noun

Slide trombone (tenor in B flat), Boosey & Co., London, c. 1875

Wiktionary

Pronunciation: /ˌtɹɒmˈbəʊn/ / /tɹəmˈbəʊn/ / /ˌtɹɑmˈboʊn/

noun

Etymology: Borrowed from Italian trombone, from tromba (“trumpet”) + -one (augmentative), literally “large trumpet”. The telecommunications sense alludes to the shape of the musical instrument.

A musical instrument in the brass family, having a cylindrical bore, and usually a sliding tube (but sometimes piston valves, and rarely both). Most often refers to the tenor trombone, which is the most common type of trombone and has a fundamental tone of B♭ˌ (contra B♭).
“Jim plays the trombone very well.”
“This trombone is very expensive.”
The common European bittern.
A kind of extendable support for attaching lighting elements to a set.
“The trombone […] permits an instrument to be positioned over a studio set wall, enabling the set wall to support the weight of the instrument.”
“The two secondary controls are the trombone handle and the focus knob.”

verb

To transmit a signal or data back to a central switching point before sending it out to its destination.
To extend and retract (the zoom lens); to use it too enthusiastically.
“[…] do things wrong (like rotating the lens turret while shooting or backwinding and doing multiple passes on the same strip of film or doing in-camera fades with the variable shutter or tromboning a zoom lens like a teenager on acid, etc., etc., etc.) […]”
“He recalls (email to editor, 2 December 2012) that Durgnat 'shouted out' in response to his 'tromboning' the zoom-lens at the film's 1967 London Film Festival screening: […]”