Definition - What does Senescence mean?
From a biological standpoint, senescence is the gradual deterioration and aging of cells. This can be due to aging, oxidative stress or other environmental factors, which can cause stress or the breakdown of cells and their function.
In the case of wine, senescence is the aging of wine, which can occur naturally with time or under less than ideal conditions.
WineFrog explains Senescence
Senescence in wine can occur under harmful conditions, which are not favorable. If there is too much light exposure, this can cause the wine to prematurely age and break down natural preservatives which exist in wine such as tannin.
If corks dry out, this can cause oxidative senescence, damaging the wine.
From the standpoint of consuming wine, recent laboratory studies have shown that wine can reverse senescence in humans and aging cells.