Ad-lib

Ad-lib is one of the most common Latin phrases used in English. Ad-lib is the shortened version of "ad libitum" which is Latin for "at one's pleasure" or "as you desire." Sometimes it is translated as meaning "at liberty" simply because of that "lib" syllable, but that is not an accurate translation.

The most common use in drama when used to describe times in performance when a performer uses words not found in the text. (When the entire performance is spontaneous and unscripted it is called improvisation.) This occurs on the live stage, in films, on television and frequently in situations such as the conversations on talk-shows, news, podcasts etc.

Larry David's HBO series, Curb Your Enthusiasm, is often pointed to as an example of ad-lib drama. The show can also be said to use "retroscripting." The series also has created its own collection of words and phrases, as noted in the video shown here.

Less well known is its use as a direction in sheet music where "ad libitum" indicates that the performer or conductor has one of a variety of types of discretion with respect to a given passage.

Ad libitum is also used in psychology and biology to refer to the "free-feeding" weight of an animal when the animal eats as it wishes rather than its weight on a restricted diet.

Boilerplate

NASA engineers inspect and test a boilerplate Mercury space capsule.
Image: NASA on The Commons

You will sometimes hear material referred to as being "boilerplate."

In my own academic work, it is sometimes used to describe a general statement, such as a grading policy, used as a starting place that teachers can modify to their needs, or sometimes, it is used "as is."

I have also heard it used to describe standardized pieces of text for contracts, and as a portion of a computer program. As the illustration above shows, it can also be used to describe a non-textual object.

In newspaper publishing, before the days of digital printing. There was syndicated material supplied to smaller newspapers in a printing plate form. This was particularly true for weekly newspapers who could use these feature stories, editorials, etc. supplied by large publishing syndicates. Rather than having to set type for the story, it was delivered on metal plates with the type already in place. They were given the name "boiler plates" because they looked like the plating used in making steam boilers.

The word "boilerplate" was used to refer to the printed material on the plates as well as to the plates themselves. Boilerplate stories were often more considered "filler" than hard news, and so the the word acquired a negative connotation. Some modern dictionaries will list its meaning as including the sense of boilerplate being hackneyed, unoriginal or clichéd writing that expresses a generally accepted opinion or belief.

You will also still find it meaning the rolled steel used for making boilers. And a more specialized meaning, as used in climbing, is to describe smooth, overlapping and undercut slabs of rock.

Rx (prescription)

I found several different theories about the origin of this symbol "Rx" used by doctors before a prescription. Is it an abbreviation? Is it some ancient chemical symbol?

Several origins sound less credible. One source said that Rx is a corruption of the symbol for Jupiter and that a prayer to Jupiter would speed healing. That doesn't make sense to me since Jupiter (also known as Jove) was the god of the sky and thunder and king of the gods in Ancient Roman religion and mythology and not associated with healing.

I couldn't find a symbol for the god, but the symbol for the planet looks like an odd 4 and is said to represent an eagle, which is Jupiter's bird.

Another theory is that the Rx symbol evolved from the Eye of Horus, an ancient Egyptian symbol associated with healing powers. This has a bit more believability because pharmacy has been around for thousands of years and the first recorded prescriptions were etched on a clay tablet in Mesopotamia around 2100 B.C. There were the equivalent of drugstores in Baghdad in the eighth century A.D.

The problem is that the Eye of Horus (also known as wadjet, wedjat or udjat) though it is an ancient Egyptian symbol of protection, royal power, and good health, doesn't look like the Rx.

The most likely origin is that this symbol seen on doctor’s prescription pads and signs in pharmacies is derived from the Latin word “recipe,” meaning “take.”  The word recipe has had the same function from the 13th through the 17th centuries. The two letters were a 19th-century way of easily reproducing a 16th-century symbol - the letter R with a line through its slanted leg.
℞  that meant the "R" is functioning as an abbreviation - not an X.
It wasn't till around 1911 that "Rx" came to be used as meaning the the noun "prescription." A recipe associated with cooking came into being in the early 17th century, which is when America’s earliest drugstores came into being in big cities. The first college of pharmacy in the United States was founded in 1821 in Philadelphia.

Today in America, the centuries old mortar and pestle - tools of the trade - is often used by pharmacists as an industry symbol along with Rx.