1. grown, aged. Ripe, mature, mellow refer to that which is no longer in an incomplete stage of development. Ripe implies completed growth beyond which the processes of decay begin: a ripe banana. Mature means fully grown and developed as used of living organisms: a mature animal; a mature tree. Mellow denotes complete absence of sharpness or asperity, with sweetness and richness such as characterize ripeness or age: mellow fruit; mellow flavor.