Hello horselydown86
Thank you for your sharp eye on that word!
Yes, I think you are right... I checked the term jointure and found it is
"A life estate that reverts to a wife after her husband's death. noun. (law) An estate settled on a wife, which she is to enjoy after her husband's death, for her own life at least, in satisfaction of dower. noun."
After trying to read the lengthy text of the document on the reverse, I managed to find that David Thomas Gllm was a reputed son of Thomas David Gllm and Anne Williams daughter of John Williams gentleman. I think it states that the property was to pass after his death into the hands of Anne Williams, David Thomas Gllm and in turn to other reputed sons of Thomas David Gllm including; William Thomas, Morgan Thomas and Howell Thomas.
David Williams of the Middle Temple London Esq. was one of the new owners of Bailie Brith, Merthyr Cynog. It is very likely that John Williams and Anne Williams were his children. David Williams was very successful and became Sir David Williams of Gwernyfed . He was the youngest son of Gwilym ap John Vychan, of Blaen Newydd, Ystradfellte, a cousin of Sir John Price of Brecon. David's patronymic name would have been David Gwilym (Gllm) ap John Vychan. He used the anglicised name of Williams by 1575.
Many thanks to you all!
Llanfi