In 2007 on the Outer Hebridean Isle of Lewis, I was given an extraordinary document. It was entitled Some Lewis Moorland Terms: A Peat Glossary, and it listed Gaelic words for aspects of the moorland that fills Lewis’s interior. Reading the glossary, I was amazed by its glittering particularities: èit refers to ‘the practice of placing quartz stones in moorland streams so that they would sparkle in moonlight and thereby attract salmon to them in the late summer and autumn’, while rionnach maoim means the ‘shadows cast by clouds on moorland on a sunny, windy day’.

Reading that Peat Glossary set my head a-whirr with wonder-words. But it seemed to me an anomaly. For our available language for and knowledge of everyday nature is, surely, becoming depleted – especially among children.

A 2016 research paper by Cambridge University conservationists found that eight- to 11-year-old schoolchildren were ‘substantially better’ at identifying common Pokemon characters than common species of British wildlife. Out of the 53 million words used in the 120,000 submitted stories for the BBC’s 500 Words competition (open to children aged five to 13), words for nature were notably rare. ‘Acorn’ was used just 293 times, for instance, ‘buttercup’ 167 times and ‘conker’ 155. This retreat of both knowledge and experience of nature has corresponded with a drastic loss of species and habitat in Britain and beyond – 53 per cent of species in the UK are in decline but 52 per cent of the British public are unaware of this situation.

In response, I decided to set out and gather as many place-words for aspects of nature, landscape and weather as possible, from the many dialects and languages of our islands. Once gathered, I wanted to find ways to release these words back into imaginative circulation, in the hope of enriching and diversifying our language for the living world.

So I travelled to meet the users and keepers of such place-words around Britain and Ireland: crofters, farmers, sailors, fishermen, naturalists, artists and countless everyday people who knew and loved their particular landscapes. I pored over glossaries and dictionaries in archives and on the web, and I sent out letters and emails to hundreds of people.

Wild words came whirling in. Foggit: a Scots term meaning ‘covered in moss or lichen’; shuckle, a Cumbrian term for ‘icicle’, or pirr, Shetlandic for a ‘light breath of wind that ruffles the surface of the water’; zawn, Cornish for a wave-smashed chasm in a sea-cliff; smeuse for the ‘hole in a hedge made by the repeated passage of small animals’. Some of these words were beautifully poetic, some dramatic, some thrillingly precise – and some unspeakably rude.

Word of the day: "solastalgia" – psychic distress of those whose home landscapes are being transformed, eg by climate change. Glenn Albrecht pic.twitter.com/4E2Q6NoLnf

— Robert Macfarlane (@RobGMacfarlane) March 22, 2017

My word-hoard filled up. By 2014 it held over 3,000 terms from more than 30 languages, dialects and idiolects, from aftermath (the ‘first fresh growth of grass after a meadow has been cut’) to zwer (used on Exmoor to denote the ‘sound made by a covey of partridges taking flight’). These were published in the spring of 2015 in a book called Landmarks. I’ve also taken to tweeting out a Word of the Day as another means of dispersing this old-new language. The word-hoard project has also inspired nurseries, schools, charities and festivals up and down the country, and comparable glossaries have been begun for landscapes including the Florida Everglades, the Swiss Alps and the Vermont hills.

Now that word-hoard forms the basis of an exhibition at Wordsworth House in Cockermouth, Cumbria – childhood home of William and Dorothy Wordsworth, both famed for the sharpness of their perception. The poet Samuel Taylor Coleridge noted that Dorothy’s ‘eye [was] watchful in minutest observation of nature’. Her writing shows her to have been especially attuned to tiny detail rather than grand spectacles, and took joy in noticing subtleties: plays of light on the fells, textures of moss on stone, ‘an under-grove of hollies’. In her prose, the Lake District appears as what she memorably called ‘a living prospect’.

Word(s) of the day: "desire paths" – tracks & trails made by the wishes of walkers, contrary to design or planning; free-will ways. pic.twitter.com/9r9Nm6DnGM

— Robert Macfarlane (@RobGMacfarlane) March 28, 2017

In the exhibition, individual words are placed in relation with striking photographs illustrating the aspects of the living world they name, taken by my photographer parents, John and Rosamund Macfarlane – who live in the northwest Lakes. On display are also original manuscripts by the Wordsworths, and some of the thousands of letters and postcards I was sent while compiling the word-hoard.

Why does any of this matter? The American essayist, farmer and activist Wendell Berry gives the best answer: “People exploit what they have merely concluded to be of value but they defend what they love, and to defend what we love we need a particularising language, for we love what we particularly know.” Amen to that.

Robert Macfarlane’s new exhibition, The Word-Hoard: Love Letters to Our Land, runs until September 3; nationaltrust.org.uk/wordsworth-house. All photos on this page were taken by Robert Macfarlane’s parents, John and Rosamund

@RobGMacfarlane

Environment

Robert Macfarlane: The nature of our words