on (someone or something)

About or detailing someone or something. Here's the report on Crimea that you wanted for the article. I've got some scandalous information on the senator that is sure to sink his reelection campaign.

on (something)

1. Taking medication of some kind. Is the patient on anything that might interact negatively with the treatment drugs? My doctor put me on steroids to treat my hay fever.

2. Experiencing the physiological or psychological effects of some illicit or recreational drug. He's acting so weird. Do you think he's on drugs? I watched the movie on acid, and it was one of the most mind-blowing experiences of my life! The athlete was disqualified when it came to light that he was on speed during the race.

on something

set phrase On some drug or medication, especially one that is altering one's behavior, perception, or cognitive abilities. He's acting so weird. Do you think he's on something?