Having developed or ripened beyond the optimal point, often resulting in a decline in quality or usefulness. The overmature fruit was too soft and had started to ferment.
Exceeding the usual or expected level of maturity, often implying a negative connotation of being past one's prime. The overmature cheese had a strong, pungent odor that was off-putting to some.
In forestry, of a tree or stand that has grown beyond the age or size at which it yields optimal growth or economic return. The foresters scheduled the overmature trees for selective harvesting.