Take two aspirin and call Ben Casey.

Dear Word Detective: I’ve been reading your articles for seven years, both for the humor and the knowledge they contain. Recently, I have been unable to determine the origins of a term: “gtts.” It is an abbreviation for the word “drops,” commonly used in the health care sciences (nursing, medicine, and the like). Other abbreviations used are “prn,” which stands for “as needed” and “stat,” which stands for “immediately.” I am eagerly hoping that you will answer my question. — Eric Desquitado.

Seven years? Wow. You should cash in your frequent flyer points. I believe you may be entitled to a free cat. Maybe two.

It may be a sign of something that prior to reading your question I had never, as far as I recall, seen the abbreviations “gtts” or “prn.” I have, of course, heard “Stat!” shouted by hyperventilating actors on TV shows with a medical theme, although the last one of those I watched with any regularity was probably “Doctor Kildare.” By the way, whatever happened to those cool white tunics doctors used to wear on TV? All the doctors I’ve seen in recent years have been dressed like lawyers in lab coats. Nice tie, Doc. I hope it’s machine-washable.

“Stat,” as you say, means “right now,” and is simply an abbreviation of the Latin adverb “statim,” meaning “immediately.” “Prn” does indeed mean “as needed,” and is an abbreviation of the Latin phrase “pro re nata,” which literally means “for the thing born” or, figuratively, “for the affair arisen.” The phrase has been used in non-medical contexts to mean “for an occasion as it arises” since the 16th century (“It was formerly left to the crown to summon, pro re nata, the most flourishing towns to send representatives to parliament,” Blackstone, 1765). “Prn” scribbled in a doctor’s prescription is, fortunately, always translated by the pharmacist to “as needed” on the medicine label.

“Gtt” or “gtts” turns out to be a remarkably interesting little abbreviation. Used to mean “drop” in prescriptions, it’s short for “gutta,” Latin for “drop” (“gtts” stands in for the plural, “guttae”). “Gutta” is also the root of our modern “gutter,” which carries raindrops away from our roofs and sidewalks. It’s also the source of the word “gout,” an unpleasant disease thought in ancient times to be the result of an imbalance in the four “humours,” fluids believed to be essential to the health of the human body. The connection between another sense of “gout” and “gutta” is more direct — we speak of “gouts” of blood meaning large splashes or spurts of blood from a serious wound.