Ray and his partner won the tennis tournament at their club yesterday. The skies threatened but luckily it didn't rain and the players were able to enjoy their strawberry tea as well. (And I didn't threaten Ray with today's word of the day before he went off to the tournament!)
It means 'mad dog' or 'lunatic dog' and is just a joke on Jinks' behalf (or is it a joke?!!)
I'll tell(show) him what you said, Gerry!