Old Tom

extra strong gin; sometimes termed cat's water. Various reasons are given for the use of the words Old Tom. The distillers have the sign of a tom cat on their illuminated placards. The origin of the phrase is, however, in the fact that the managing clerk of a once celebrated “gin-spinning” firm, who was known as Old Tom , used to keep a special bottle of extra good stuff with which to regale customers when they settled their accounts. To get a drink of Old Tom's  was then a great favour. Gradually the title became popular as representing very good strong gin.