1. not mature, ripe, developed, perfected, etc.
2. emotionally undeveloped; juvenile; childish.
3. Physical Geography. youthful (def 5).
4. Archaic. premature.
"people can be immature in battles."
"people can be immature at ages."
"insurances can be immature as sectors."
"bases can be immature for generations."
"people can be immature."
This list can help you learn new vocabulary more quickly and be able explore other words more easily.