Plain English Meaning
Drinks that make you urinate more, so they cause your body to lose water faster than you take it in. Coffee, tea, cola, energy drinks, and alcohol all do this.
Full Definition
Beverages that increase the body's production and output of urine, accelerating fluid loss. Common diuretic drinks include coffee, tea, caffeinated soft drinks, energy drinks, and alcohol. For pilots, consuming these drinks during flight can speed up dehydration rather than relieve it.
Context Anchor
Seen in aeromedical guidance about dehydration, heat exposure, and pilot fitness before or during flight.
Derivation
From the Greek 'diouretikos,' meaning 'promoting urine.' Knowing the root makes the warning clear: a diuretic drink actively pushes fluid out of the body, which is the opposite of what a thirsty pilot needs.