rhubarb

1. Any plant of the genus Rheum, especially Rheum rhabarbarum, having large leaves and long green or reddish acidic leafstalks that are edible, in particular when cooked (although the leaves are mildly poisonous).
2. The leafstalks of common rhubarb or garden rhubarb (usually known as Rheum × hybridum), which are long, fleshy, often pale red, and with a tart taste, used as a food ingredient; they are frequently stewed with sugar and made into jam or used in crumbles, pies, etc.
3. The dried rhizome and roots of Rheum palmatum (Chinese rhubarb) or Rheum officinale (Tibetan rhubarb), from China, used as a laxative and purgative.
4. A Royal Air Force World War II code name for operations by aircraft (fighters and fighter-bombers) involving low-level flight to seek opportunistic targets.

verb

Of fighter aircraft: to fire at a target opportunistically.

adjective

Of the colour of rhubarb: either brownish-yellow (the colour of rhubarb rhizomes and roots used for medicinal purposes), or pale red (often the colour of the leafstalks of common rhubarb).

1. (originally theater) General background noise caused by several simultaneous indecipherable conversations, which is created in films, stage plays, etc., by actors repeating the word rhubarb; hence, such noise in other settings; rhubarb rhubarb, rhubarb rhubarb rhubarb.
2. (originally baseball) An excited, angry exchange of words, especially at a sporting event.
3. (originally baseball, by extension) A brawl.

1. (originally theater) Of an actor in a film, stage play, etc.: to repeat the word rhubarb to create the sound of indistinct conversation; hence, to converse indistinctly, to mumble.
2. To articulate indistinctly or mumble (words or phrases); to say inconsequential or vague things because one does not know what to say, or to stall for time.