(1) Retirement is the point where a person stops employment completely.
(2) A person may also semi-retire and keep some sort of retirement job, out of choice rather than necessity. This usually happens upon reaching a determined age, when physical conditions don't allow the person to work any more (by illness or accident), or even for personal choice (usually in the presence of an adequate pension or personal savings). The retirement with a pension is considered a right of the worker in many societies, and hard ideological, social, cultural and political battles have been fought over whether this is a right. In many western countries this right is mentioned in national constitutions.
To be honest, I haven't a clue what to do with the rest of my life. I was brought up with the work ethic and have followed it for 44 years, so to stop now will be like losing a loved one.
On the other hand should I make use of the time to spend my life getting pissed every day in the pub, and run the risk of the pub closing down as I drive the other customers away with my boring sea stories.
The decision is yours!