More words which have dramatically changed their meaning over the centuries.
Nowadays, when we use the word gamut we use it to indicate the full extent or scope of something as in he went through the gamut of emotions. But it wasn’t always ever thus. When musical theory first developed and a system was devised to denote and differentiate between notes in the scale, appropriate nomenclature was developed. The first and lowest note in the scale was called an ut and the lowest of all the possible uts was called the gamma ut which through a process of elision became known as a gamut. In time the term gamut was used to denote the whole range of notes in a musical scale. Shakespeare uses it thus in Act Three of the Taming of the Shrew in a musical context where Bianca discusses the names of the notes in the musical scale. It was only in the mid 18th century that it firstly lost its specific association with music and gained the more generic meaning that it has today.
To be ambidextrous these days is to be considered skilful because it means you can use your weaker hand just as well as your stronger hand. But in the mid 16th century when the adjective first appeared in the English language you might not be too pleased to be labelled with it. An ambidexter was someone who took bribes from both sides in a legal case and so the original meaning of the adjective was duplicitous or two-faced.
Many of us are on the look out for a thrill, a sudden feeling of excitement or pleasure, to brighten up our mundane existence. But its original meaning as a verb was to put a hole into something. The origin of nostrils, the orifices in our schnozzle, is from nose-thrills ie holes in your nose. It developed its more figurative meaning sometime during the 16th century, presumably in the context of being something that could affect you deeply.
Someone who is volatile is someone who is emotionally unstable and likely to fly off the handle. The Latin root for the word is the verb, volare, which means to fly and volatile in English was initially used as an adjective applied to birds which were capable of flight. The word was then used to describe chemicals or compounds that were liable to disperse in fumes. It was not until the middle of the 17th century that it developed its figurative meaning of fickle or changeable.
Egregious is a wonderful word. Today it is used as an adjective indicating something particularly bad or horrendous as in egregious behaviour meaning atrocious conduct. But as any student of Latin would tell you, its original meaning was the polar opposite, something which stood out (ex) from the crowd (grex). It is thought it was used in the opposite and modern-day context in a satiric fashion. Whether that is true or not, its usage has stuck.
For schoolboys deprived of the opportunity to read Aristophanes – far too many, alas, these days – there is ample opportunity for tittering in the class in the study of 19th century English novelists and their use of the verb ejaculate. There are more ejaculations than even Christian Grey could manage. Of course, to ejaculate in those days meant to exclaim or to utter suddenly and passionately rather than its more tawdry definition today.