A mixture of rum and water, sometimes sweetened with lime and sugar. Issued on British Navy ships from the mid 18th Century to the late 20th Century.

grog is a word used by aussies which means alcahol

Grog is a secret mixture that contains one or more of the following:
-kerosene
-propylene glycerole
-artificial sweeteners
-sulphuric acid
-rum
-acetone
-red dye #2
-scumm
-axle grease
-battery acid
-and/or pepperoni

As you can imagine, it's one of the most caustic, volatile substances known to man.

Cavalry Grog has a long tradition of identifying true cavalrymen.

The history of the "Punch Bowl" ceremony has become obscured with time. Legend has it that during the years of the Westward expansion, Cavalry Troopers would share their spirits with one another thereby insuring that all fellow troopers had something to drink. The alcoholic spirits usually consisted of whatever an individual trooper’s taste was, and that when mixed with other alcohol created a powerful drink known as "GROG". The camaraderie developed over the decades, and the various wars and campaigns provided the rare opportunity to share "liberated" spirits with each other. Today’s "GROG"
or punch bowl ceremony is a symbolic reflection of this age-old tradition.

A diluted mixture of rum that originally included sugar and citrus juice. Slang associated with it is "Tanky", the server of it. Served in a "can" no matter what the vessel was. It was discussed in its water to rum ratio by compass points and in numbers, north being pure rum and east being water. The authentic recipe is so short and excellent, I'll give it to you:
Grog 1:4/four-water
half cup rum
pint water
1/8 cup sugar
" " lime or lemon

A drinking game where players attempt to shoot multiple quarters into an ice cube tray and drink from a community cup called "the grog."

The singer from Gothic Metal band, Die So Fluid