The antonym for the word "more hardshelled" is "less hardshelled." Hardshelled refers to something protected by a tough outer layer, such as a nut or crustacean. Therefore, less hardshelled would describe something that is not as tough or protected. Instead, it may be more vulnerable or soft. Possible synonyms for less hardshelled include fragile, flimsy, soft, tender, or delicate. Conversely, some antonyms for less hardshelled might be more robust, fortified, resilient, durable, or sturdy. Ultimately, the choice of antonym depends on the context of the sentence and the intended meaning.