Today this word is taken to refer to a seer or prophet. But what is a prophet? It has two related but different meanings.
The first is one who speaks by divine inspiration. This is the sense in which Muhammad is said to be the prophet of Allah. Allah speaks through Muhammad, the Quran is divinely inspired and so the word of god. Plainly, if there were no divinity, this definition of the word prophet would be devoid of meaning.
The word ‘prophet’ is also used to mean someone who predicts the future, and this is the denotation carried by the verb ‘to prophesy’. In this sense, prophets occur in Hebrew scripture, where the gentlemen in question (they are always men) are given to predicting that the wrath of God will fall upon the chosen people if they don’t mend their ways, live a more moral life, stop adding yeast to their bread and so on.
Though many people claim an ability to predict future events – astrologers, tipsters, assorted preachers – few are so vainglorious as to call themselves prophets.
The word ‘soothsayer’, seldom used these days, was free of all this baggage back in the old days where, as some of you must suspect by now, I like to pitch my tent. All it meant was someone who told the truth. It comes from the Anglo-Saxon words truth and say – soðsagu.
In the untitled poem we call The Wanderer, the poet says at one point, ‘Ic to soðe wat,’ meaning ‘I know it to be true’. What did he know to be true? That it was a good idea to keep your thoughts to yourself, whatever you might think. I was much influenced by this poem and have remembered the following lines since I first came across them. The poem is written in the four stress alliterative line.
Ic to soþe wat
þæt biþ in eorle indryhten þeaw,
þæt he his ferðlocan fæste binde,
healde his hordcofan hycge swa he wille.
A lingering death-blow was dealt to this culture by the invasion of William the Bastard and the importation by the Norman French of their language and repressive feudal system, small vestiges of which remain with us to this day.
I do not read fantasy fiction, but I would guess that might be a good place to look for instances of the word soothsayer still in use today. Another fruitful area might be historical fiction.