Sentence:  Sometimes there is confusion over the heraldic <WSD>leopard</WSD>, the question being—When is a <WSD>leopard</WSD> not a <WSD>leopard</WSD>? There is a theory that the lion and <WSD>leopard</WSD> were the same thing, and that they were named entirely depending on their attitude—thus if the animal was passant guardant it was a <WSD>leopard</WSD>, but when rampant it was a lion. Nowadays a <WSD>leopard</WSD> is the genuine spotted article and quite unmistakeable. Some people still speak, wrongly, of the <WSD>leopards</WSD> of England, but it does no great harm as it is an ancient expression and everybody knows what it means. 
Meaning of the word marked with <WSD> tags:  A lion passant guardant.