I read an interview with Babyface (the singer/producer) many years ago. he identified what he called "mushmouth" as a common element of hit songs. The singer shouldn't have perfect pronunciation. He sited the example of "Manfred Mann's Earth Band- Blinded by the Light". it seemed everyone sang along with that song. Also seemed nobody could figure out what he was singing on "wrapped up like a ?????". It gets people to listen over and over, and in the day request the song on the radio. It gets you addicted.
I think they used that on this track. It works!
Notice how Adele doesn't pronounce perfectly. You have to listen to clearly, and repeatedly, to get some of the words.
a thought... we will never know what it means because it works to get people hooked and create a singalong song.
and the Wachowski brothers will never explain The Matrix LOL