I was a child often distracted by language’s strangeness. Learning the meanings of difficult words proved more enjoyable than board games. Particularly distracting were the traces of earlier history that I could detect in the wording of Christmas carols. Why were the steeple bells ordered to be ‘swung-en’? In what way might the baby Jesus be ‘very’ God? Was he super-extra divine or something not yet understood by me? I pestered the adults around me for explanations and poked my little fingers into the thumb index of the big dictionary at the front of the class.

Impossibly intriguing, to a child of my persuasion at least, was the Burt Reading Test. You were handed a laminated sheet with sets of words, from the very simplest to groups of words like ‘phlegmatic’, ‘melancholy’ and ‘palpable’. I realise, in retrospect, that it didn’t matter if you knew what the word meant. The test was simply whether you could say it correctly – not exactly a reliable assessment of comprehension. You carried on until you mispronounced one and then the test was over. Next, after tabular prognostication, your reading age was announced – 11.2 years, say, or 14.5. Most of my fellow pupils found it an ordeal, but for me it was an annual thrill.

At the point of failure (for several years this being the word ‘poignancy’, which I invariably began poe-ig), I would take a glance at the trickiest words before they were put back in the file. Words like ‘alienate’ or ‘phthisis’ were hard to memorise, but I yearned to know what they meant and how they meant it. The dictionary told me that ‘phthisis’ was a name for tuberculosis, its onomatopoeic cough-splutter of consonants coming from a Greek verb for ‘to decay’. ‘Alienate’ came via French and Latin words for ‘foreign’ and ‘strange’. Much later in life this helped me decipher what exactly an alien priory might be.

Ralph Waldo Emerson, in one of his published lectures, claimed rhapsodically that poets were the original name-givers and language-makers. The process of giving a thing of the world a name embedded within the word a kind of poetry:

The etymologist finds the deadest word to have been once a brilliant picture. Language is fossil poetry. As the limestone of the continent consists of infinite masses of the shells of animalcules, so language is made up of images or tropes, which now, in their secondary use, have long ceased to remind us of their poetic origin.

Emerson’s concept of ‘fossil poetry’ reflects the age he lived in, one of geological and palaeontological discoveries. Recently, while writing my book Mother Tongue, I’ve been fossil-hunting for words relating to women’s bodies, lives and experiences. There’s much sexism in our vocabulary’s stony sediments, of course. Unmarried men are ‘bachelors’, a word which also named a young knight, a junior guild member and a university graduate, while unmarried women are ‘spinsters’ thanks to the association between single women and the low-paid work to which they were largely confined. But there are also gentler examples. Your alma mater, for example, is your nurturing mother, a phrase used rhetorically in medieval Latin to characterise a university’s relationship with its students. Your fellow alumni are your fellow nurslings or foster siblings, nurtured alongside you.

My investigations have led me to the poetry of plainer words, too. There were once plenty of ordinary terms for menstruation, predating the more euphemistic ‘monthly period’, which was first recorded in the 1690s. Such words appear in some of the first dictionaries to give English definitions for words in other languages, wordbooks which were often dedicated to aristocratic women patrons. John Florio in his Queen Anna’s New World of Words (1611) defines the Italian menstruo as ‘a woman’s monthly terms, issues, fluxes, sheddings or flowers’, giving a gush of synonyms for this everyday occurrence.

The Latinate names we now use for female sexual anatomy have generally come into English through the translation of medieval textbooks and through early modern guides to the discoveries of Renaissance anatomists. ‘Vagina’, notoriously, began life as an analogy, comparing the body part to the sheath of a sword. Alongside first instances of Latin and Greek terms, English translators often provided vernacular equivalents, which name by metaphor: ‘port’ and ‘passage’, ‘cleft’ and ‘chink’, ‘neck’ and ‘leaf–gates’, ‘lap’ and ‘wings’.

Why did synonyms like these fade away when Latinate names took hold? Notions of decorum and prudery gripped society more firmly in the decades after 1700. Eighteenth-century dictionaries advertised themselves as suitable for ‘female readers’ with all ‘obscene’ or ‘indecent’ terms now omitted. As public speech became more restrained, medical and scientific experts consolidated technical terminology. Yet if the plainer anatomical synonyms had caught on instead, we might feel rather more at home with medical language. Surveys today report that many of us aren’t always confident or accurate in matching label and body part. Feelings of taboo contribute here, of course, but the Sunday-best formality of the vocabulary doesn’t help.

Jane Sharp, a midwife who published an obstetrics textbook in 1671, knew that technical terms were not always a great help at the business end of childbirth. As she drily noted in her Midwives Book, it’s not ‘hard words that perform the work, as if none understood the Art that cannot understand Greek’. Male doctors might have had book learning, but before the arrival of the so-called man-midwives, the expertise needed to deliver babies safely lay mostly in women’s hands. For midwives wanting to improve their anatomical knowledge, these technical terms were, said Sharp, ‘but the shell’ on which we often ‘break our teeth’. Yet she told her fellow midwives that she wanted ‘our brains to know what is the meaning of them’. Sharp both explained the hard words and also gave glosses and descriptive synonyms.

Now being in the foothills of middle age, I’ve come round to Sharp’s way of thinking, though the girl who adored hard words for their tooth-cracking difficulty still resurfaces whenever I turn to a dictionary for help. These days I like the plain and hands-on glosses as much as the fossil poetry.