French Acronym for "Rien du tout", which means "nothing at all". Pronounced "err -deh-teh" or "raw-deh-teh.
It can be used in any language to signify the absence of objects, feelings, perception while sounding blasé and borderline confusing.
- You okay? What's wrong? - Rdt.
- Is there anything on my face? -aside from your usual scowl, Rdt. you're good.
My employer said they use an RDT system to make sure nobody has huffed paint.