In 1926, the American economist Thorstein Veblen wrote The Theory of the Leisure Class: An Economic Study of Institutions. It should have been entitled "The Lives of the Idle Rich".
Veblen egregiously misused the word "leisure" for idleness and recreational activities, the sports and games at which the idle rich played when they were not engaged competitively in what Veblen called "conspicuous consumption" of clothing, jewelry, and real estate.
Not having to toil for a living, and not being given to the often exhausting details of real leisure-work, they had ample free time to disport themselves or be bored. Veblen also misused the word "leisure" for time that is free, not for an activity like work that consumes time usefully, even when it is not compensated at all.
The English word "leisure" derives from the Latin licere, which means an activity that is permissible. This meaning runs counter to the understanding that leisure work is not only permissible but also morally obligatory for anyone trying to live a morally good life.
The English word "leisure" also translates the Greek word schole as "school" and stands for an activity that involves learning or self-improvement.
When this meaning is fully understood, the mistake will never be made of using "leisure" to denote "free time" or regarding leisuring as a synonym for playing and recreation.