Ten years ago, on the Outer Hebridean island of Lewis, I was given an extraordinary document. It was entitled ‘Some Lewis Moorland Terms: A Peat Glossary’, and it listed Gaelic words and phrases for aspects of the tawny moorland that fills Lewis’s interior.

Reading the glossary, I was amazed by the compressive elegance of its lexis, and its capacity for fine discrimination: a caochan, for instance, is ‘a slender moor-stream obscured by vegetation such that it is virtually hidden from sight’, while a fèith is ‘a fine vein-like watercourse running through peat, often dry in the summer’.

Other terms were striking for their visual poetry: rionnach maoim means ‘the shadows cast on the moorland by clouds moving across the sky on a bright and windy day’; and teine biorach is ‘the flame or will-o’-the-wisp that runs on top of heather when the moor burns during the summer’.

The ‘Peat Glossary’ set my head a-whirr with wonder-words – and it prompted me to begin collecting and organising words for weather, nature and landscape from across Britain and Ireland. After eight years’ work, I had more than 2000 words from over thirty languages and dialects, from Orcadian (grimlins: ‘the night-hours around midsummer in the far north when dusk blends imperceptibly into dawn’) to Cornish (zawn: ‘a wave-smashed chasm in a sea-cliff’). I published these words in nine glossaries, as part of my book Landmarks, about the relations of landscape and language.

I knew, though, that there would be many more such words in existence: words made fragile by the passing of time and the changing of circumstance. I hoped that the publication of Landmarks would encourage people to share their words with me.

It did. In the year since Landmarks was published in hardback, I have been sent more than 4000 words by postcard, letter, email and tweet, sent from around the world. Along with the words have come books, stories, photographs, maps and memories. It has been one of the great surprises and privileges of my writing life to receive this correspondence.

Among the letters have been a poem written by a father for his daughter, combining place-names and bird-calls; a postcard carrying a list of English fishermen’s words for the watches of the night: light moon flood, light moon ebb, dark moon flood, dark moon ebb (which became a lyric that tided in my mind for days afterwards); and a weather-book of Orcadian wind-and-snow words, with a head of bog-cotton pressed between its pages.

My correspondents have included a Virginian hill-farmer, a Californian environmental lawyer, a man whose family had farmed the same land on the Isle of Wight for more than 600 years, a 96-year-old lady from Lancashire, a lollipop-man, and an intensive-care nurse. I am so grateful to the many hundreds of people who wrote to share their knowledge and stories.

The paperback edition of Landmarks, published this May, carries a new chapter describing the correspondence I’ve received, and the unexpected lives that the book’s ideas and words have lived since publication. It also includes a fresh glossary – the ‘Gift Glossary’ – containing 500 of the most memorable place-words I’ve been sent: from aime (‘shimmering air visible above the ground in hot weather’: Caithness) through bread-and-cheese (‘edible young spring shoots on a hawthorn hedge’, Cheshire), petrichor (literally stone essence: ‘the distinctive smell of rain in the air, sometimes detectable before rain has even begun to fall, and especially strong when the first rain falls after a long, hot, dry period of weather’), all the way to zebn-slaper (literally seven-sleeper, a Somerset term for a dormouse).