Carousing: a large draft of liquor

Source: http://www.merriam-webster.com/dictionary/carousing

“But Mr.Self’s has been clean for eight years or so, and some of the energy he used to expend on carousing now goes into epic hikes, sometimes as long as 100 miles.” from A Literary Visitor Strolls in From the Airport by Charles McGrath

I now understand the carousing used in the following quote because Will Self has found another way to keep his mind off drinking.