Premature (adjective)

1. Happening or done before the usual or expected time.
2. Occurring before full development or maturity.
3. Occurring before the appropriate or natural time.

Origin:

From old french premature, from latin praematurus ("too early"), from prae ("before") + maturus ("rip.e")

Examples:

1. He was born with a premature birth.
2. Her hair was turning gray prematurely.
3. It would be premature to draw conclusions from this data.
4. He was forced to retire prematurely due to health issues.
5. The company's success was seen as premature, as it had not yet proven its financial stability.