Presto can be both a term used in music to indicate a fast tempo and an exclamation used by magicians to draw attention to the completion of a trick. The word means "quickly" in Italian (and was thus used to indicate a quick change). It comes from the Latin word praestus, which meant "ready", but had a more literal definition of "stand before". It's composed of the prefix prae-, meaning "before" (and deriving from Proto-Indo-European per, still "before") and the verb stare, which meant "to stand" (and is from PIE steh, which also had the same definition). Praestus also gave us the imprest system of accounting and the first part of the name for restaurant chain Pret-a-Manger (which translates to "ready to eat"). After peaking in the year 1797, usage of the word presto has been fairly constant over time.

Today, the word hermetic is a synonym of "airtight", normally preceding some form the word seal. The term, which was first applied specifically in reference to glass bottles, originated from the world of alchemy, where potions had to be made in airtight flasks. Most of the instructions for these distillations were first written out in a fifteenth-century manuscript called the Corpus Hermeticum, which was named after its purported author, Hermes Trismegistus, a hybrid of the Greek messenger god Hermes and some other deities. The name Hermes is of uncertain origin; the best explanation out there is that it may derive from the Proto-Indo-European reconstruction ser, meaning "bind". Usage of the word hermetic peaked in 1994 and has been declining since.

The word profane precedes the word profanity by over a hundred years. It was first used in a 1450 philological journal, where it was spelled prophane. Other spellings since then have included prophain, prophaine, prophan, profeaine, profaine, profan, progayne, and more. Through Old French, the term was borrowed from Latin profanus, which meant "unclean" but also had the more literal definitions of "unholy" or "not religious" (because who doesn't love bashing atheists?). That's composed of the prefix pro-, meaning "before", and fanum, "temple"; the idea was that profane people should not be admitted into temples with more holy worshippers. Pro traces to Proto-Indo-European per, also "before", and fanum (also the root of fanatic​) is from PIE dhes, which was used to form religious words.

Petrichor is a pleasant word for a pleasant thing: the earthy aroma of rain on soil. The term was coined in a 1964 Nature article by Australian scientist Richard Thomas, who had studied the phenomenon for years. He derived the word from Ancient Greek petra, meaning "rock", and ichor, which was the mythological blood of the gods (the idea was that petrichor is the "essence" of stone, like ichor is the essence of the gods). Before the Nature article, people just referred to petrichor as "argillaceous odour". It was also previously described in Uttar Pradesh, India, as matti ka attar, or "earth perfume", which I think is a way cooler name. Both petra and ichor are of unknown, possibly Pre-Greek origin. Usage of the term peaked in 1975, decreased until 1995, and has been repopularized since.

Rickets is a skeletal disorder caused by a vitamin D deficiency that results in a weakening of bones in children. The word, first used in a 1634 London mortality report, originated from a local dialect in southern England. Because of the provincial nature of the term, the etymology is uncertain, but there's been a lot of speculation on the topic. It could be from Old English wrickken, meaning "twist" (referring to how it can cause the spine to be abnormally curved), or from the Dorset word rucket, meaning "breathe with difficulty", or from Greek rakhis, "spine". The latter seems most likely; it comes from an earlier word meaning "ridge", which was most commonly used in reference to leaves and spines. Usage of the word peaked in 1939 and has been decreasing since.

The word collusion was first used in a 1397 Chaucer poem, where he spelled it collucione. After that, some early authors wrote it as collusyon or collusioun, but collusion became the standard fairly quickly. The word, which precedes the verb collude by over a century, traces to Old French collusion and Latin collusionem, which referred to the act of colluding. That comes from the verb colludere, which meant "play together" but in a legal context meant "to have a secret understanding" (here, "play" got extended to a greater sense of "cooperation"). The roots there are the prefix cum-, meaning "with" (and tracing to Proto-Indo-European kom, "next to") and ludere, which you may recognize from the words illusion, prelude, ludicrous, delude, and others as meaning "to play" (this might be from Etruscan).