Definitions
1.nounThe state or process of ageing, especially in humans; old age.
2.nounCeasing to divide by mitosis because of shortening of telomeres or excessive DNA damage.
3.nounOld age; accumulated damage to macromolecules, cells, tissues and organs with the passage of time.
4.nounFruit senescence, leading to ripening of fruit.
5.noun(of a cell) Condition when the cell ceases to divide.