trombone

noun

1. 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.”

   “Horns, trumpets, and trombones, both soloistically and sectionally, became central to the orchestral concept... His highly subtle orchestration elevates woodwinds, more often scored soloistically than sectionally.”

   “Using the “endangered species” model employed by the World Wide Fund for Nature, campaigners are highlighting the scarcity of bassoonists and paving the way for the promotion of some other orchestral instruments that are under threat, such as the oboe, French horn, viola, trombone and double bass.”

2. The common European bittern.
3. 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

1. To transmit a signal or data back to a central switching point before sending it out to its destination.
2. (slang, transitive)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: […]”