'Thence' means 'from that place' — and by extension 'from that fact', 'and therefore from there'. It belongs to a small old family of direction words: here / hither (to here) / hence (from here), and there / thither (to there) / thence (from there). English used to keep 'to' and 'from' inside the word itself; now we just say 'from there' and let the preposition do the work.

So you will meet it mainly in travel writing, old books, legal documents and formal accounts of journeys: 'We sailed to Lisbon, and thence to Madeira.' Notice it does the job of 'and from there', in one word, without repeating the place name — that neatness is why writers still like it.

The second use is logical rather than geographical: 'from that fact it follows'. 'The lock was broken, and thence the police concluded a burglary.' Here it is close to 'hence' or 'therefore', though this use is rarer today and can sound stiff.

Be clear with your students: nobody says 'thence' in conversation in 2026. It is a reading word. Know it so that a nineteenth-century novel or a property deed does not stop you; write 'from there' yourself.