The phrase "gone by the board" means to be forgotten or lost. There are several synonyms for this expression. One of the synonyms for this expression is "vanished." When something has vanished, it has disappeared or become lost. Another synonym for "gone by the board" is "forgotten." When something is forgotten, it has been left behind or disregarded. Another synonym for this phrase is "disappeared." When something has disappeared, it is no longer visible or present. A similar phrase to "gone by the board" is "fallen by the wayside." Both expressions carry the same meaning of being forgotten or lost.