pt]
| 1. | improperly or insufficiently developed. |
| 2. | Photography. (of a negative) less developed than is normal, so as to produce a relatively dark positive lacking in contrast. |
| 3. | developing (def. 2). |
underdeveloped un·der·de·vel·oped (ŭn'dər-dĭ-věl'əpt)
adj.
Not adequately or normally developed; immature.