ripening, aging, ageing -- (acquiring desirable qualities by being left undisturbed for some time)
aging, ageing, senescence -- (the organic process of growing older and showing the effects of increasing age)
Overview of verb age
The verb age has 3 senses
age -- (begin to seem older; get older; "The death of his wife caused him to age fast")
senesce, age, get on, mature, maturate -- (grow old or older; "She aged gracefully"; "we age every day--what a depressing thought!"; "Young men senesce")
age -- (make older; "The death of his child aged him tremendously")