"stan" means stone or stony. Stanford = stony ford, Stansted= stony place There are many similar names such as Stanbridge and Stanton.
The caution comes when "stan" or "ston" comes at the end of a name. For example, you might think that Lullingstone means "the stone of Lulling". It doesn't and really means Lulling's tun. Tun can mean a farm, village or settlement. That is why you have to trace the earliest written form of the name. Spellings change so much - a favourite example comes from East London. Hoxton was Hochestone in the Domesday Book, but there is no stone there. It means Hoc's tun - ie a Saxon named Hoc once lived there and so it became known as Hoc's farm.
