Very drunk, specifically on gin.
A result of the "gin craze," British
government tried to stem the flow of gin with prohibitive taxes and rules, which drove the gin scene underground during 18th-century England. Exploiting a loop-hole in these new regulations, where a bartender couldn't be prosecuted for serving gin if the
police couldn't be sure exactly which bartender served it, wooden plaques shaped like a black
cat (hence "Old Tom gin") were mounted on the outside wall of some pubs. These
cat plaques had little paws, and under the
cat'
s paw was a slot to put money in and a small lead tube. From the tube would come a shot of gin, poured by the bartender, who remained anonymous from inside the pub.
Today, "under the
cat's paw," simply means to be very drunk on gin, perhaps to great excess, as that is where most of these gin-crazed bar-patrons would have spent most of their time.
"I'm going to be under the
cat's paw tonight!"
"Billy, if you don't slow down on those martinis, you'll be under the
cat's paw in no time!"
"I can't remember a thing- I was absolutely under the
cat's paw!"