be down with (something)

1. To be in agreement with, in support of, have interest in, or thoroughly enjoy some subject, activity, or thing. I am so down with math, it's my favorite subject in school! Yeah, I'm down with seeing a movie later this evening. Patty's down with a quick game of soccer and said she'd meet us at the park.

2. To be ill or have caught some disease. (More often expressed as "come down with something.") Marigold had to go home early today. I think she's down with the flu. I'm not surprised to hear that he's down with bronchitis. He'd been working too hard for too many days in a row. Now that graduation is so close, plenty of the kids are down with "senioritis," an apparent inability to do homework—or even show up anymore.

down with (someone or something)

A phrase used to emphasize one's opposition to someone or something, especially that the offending person or thing be removed or eliminated. It wasn't long before all the students were chanting, "Down with homework!" A: "What are the workers shouting? 'Down with overtime'?" B: "Yes, sir, it seems they're very displeased with the latest mandates." Today marks the seventh straight day of protests and chants of, "Down with the king! Down with the king!"

down with somebody/something!

shouted as a protest against somebody/something: Down with the dictator!

down with something

1. mod. comfortable with something; comfortable. (Usually with get.) Let’s get down with some good music.

2. mod. ill with something; sick in bed with something. I was down with the flu for two weeks.