The word "most overripe" refers to something that is too ripe or past its prime. Antonyms for this phrase would be "underripe," "unripe," or "immature." Underripe fruit is not fully developed and may be sour or hard, while unripe fruit has not yet reached its full potential and may lack sweetness. Immature fruits may be small, hard and not yet developed. In contrast, ripe fruit is sweet and ready to eat, while overripe fruit is past its prime and may be mushy or spoiled. Choosing the right level of ripeness is important for the taste and texture of a fruit or vegetable.