Dislimn. It's used by Robert Louis Stevenson, author of Kidnapped, in a letter to Elizabeth Ferrier, wife of Walter, a man whom he loved, and who had died.

'I always thought I should go by myself; not to survive. But now I feel as if the earth were undermined, and all my friends have lost one thickness of reality since that one passed. Those are happy who can take it otherwise: with that I found things beginning to dislimn.'

As part of a day on friendship and literature, Penny Fielding explained that Stevenson liked words that begin with 'dis', for the sense of loss and ghostly remembrance they hold. (He talked of a street being 'dispeopled'.) To dislimn means to efface, blot out, or obliterate the outlines of. It's linked with to limn, or to illuminate - as in outlining in gold on a manuscript or making visible in a watercolour.

Stevenson's shock at the death of his friend focused on the assumption that he'd go first, as he was older. That reversal highlighted to him the brutal unnaturalness of someone whom you love now being dead, it's unthinkableness. Things began to lose their outline, for Stevenson, and the world its gold edge.

Another thing that struck me from the day, was the image used to advertise it - a huge sea snake painted by William Blake, inscribed with the words, 'Opposition is true friendship.' I appreciated the esoteric, conjunctio principle presumably represented by it.