Merriam-Webster says the word "volunteer" doesn't mean what United thinks it does.
The dictionary publisher tweeted:
Lookups for "volunteer" spiked by 1,900 percent after United used the word in a statement on the incident, the dictionary said.
The dictionary editors also found the airline's use of the phrase "overbook situation" objectionable:
"News accounts of the incident made mention of the fact that the flight was overbooked, but, as dictionary people, we also notice that the airline's statement used overbook adjectivally to modify a noun, a definition that we don't yet include. This use probably shows one way that language evolves: specialized words that are frequently used within an industry sometimes undergo functional shift and may or may not spread to common usage. We volunteer to watch this one."
Merriam-Webster's editors have been trolling newsmakers lately, defining the word "complicit" for Ivanka Trump, and doing the same for the word "fact" after White House aide Kellyanne Conway coined the term "alternative facts."