1.
soft-boiled, half-cooked
Describes food, especially eggs, that is not fully cooked through. The most common usage refers to soft-boiled or runny eggs.
2.
half-ripe, not fully mature
Describes fruit or produce that has not yet fully ripened. Can also be used figuratively for a person who is still immature or not fully developed in skill.
Common collocations
Usage
The most frequent use is for eggs. In everyday Japanese, 半熟 almost always refers to the degree of cooking for eggs — runny or soft rather than hard-boiled (固茹で). The sense 2 meaning (half-ripe fruit, immature person) is less common but appears in literary or descriptive contexts.