"Drave bananas" is a specific term that refers to bananas that have been harvested prematurely in order to transport them without bruising. However, there are other synonyms that can be used to describe bananas that are not yet fully ripe. For instance, you could say that these bananas are "green," "unripe," or "under-ripe." Alternatively, you might describe them as "firm," "hard," or "inflexible," since bananas that are not yet ripe tend to be less yielding. Additionally, you could use more creative terms, such as "immature," "unseasoned," or "nascent," to convey the idea that these bananas are not yet fully developed.