What is Kgd?

Unfortunately, Kgd does not appear to be a recognized term in the glossary of chess terms. It may be a typo or an acronym specific to a certain context. In chess notation, K typically stands for King and d could refer to the d-file on the board, but the specific combination Kgd is not clear. It's recommended to refer back to the original context or clarify with the person who used the term.