Hi,
None of the other posts helped me to delete a board in Trello.
I tried chosing a board in 'recent' and in 'personal'. Hovering over there is no '...' symbol to choose. Selecting a board, which I already emptied from tasks and all lists but one, gives me the board title. Clicking it offers me the opportunity to rename the board and it stores it under the new name. o option, I ca see, to archive the board and close it, then delete it permanently.
Kindest regards, Leo.