"To bite the dust" apparently is:
"Biting the dust" is what happens when you fall face first into the dirt. It can mean a few things: for a person to die (though that would be a very crude way saying it - do not use at a funeral!), a machine to break, or in the case of the Queen song, for a competitor to lose/fall out of the competition. https://idioms.thefreedictionary.com/bites+the+dust
According to Word Reference, "mordre la poussière" means "to lose, to suffer a defeat" (https://www.wordreference.com/fren/mordre%20la%20poussi%C3%A8re). Can it also mean "to fail" and "to be killed", as the English idiom ?
The plosive 'b' and 'd' in English give the phrase urgency and violence, whereas the softer 'm' and particularly the '...oussiere' have the opposite effect. But I suppose with practice- I have, you can tell - you could sing this rhymically in time to Queen as as 'Un-au-tremord la-pouss-iere' whicjih is what they do 'An - oth - erone bites-the -dust'.
Well, sort of, but bites the dust has more of a meaning than defeated. You can say it about something you've thrown out - say, you're cleaning out your closet and throwing away clothes. As you toss something into the garbage can, you say - another one bites the dust. The piece of clothing isn't defeated. it's gone.
It's a real expression in French so it's good to know. And for anyone who knows the song, putting the French words to the familiar melody can help them memorize the new vocab. I didn't remember mordre or poussière easily before this, but having "un autre mord la poussière" playing in my head all morning will surely help with that!
I disagree. Once you start listening to real, every day speech (and paying attention to what's said in your own language), you realize that idioms like these make up a pretty high percentage of speech. It's pretty important to understand them. You lose a lot of the conversation when you don't know them.