Not ready or organized.
From the prefix "un-" meaning "not" and the verb "prepare" meaning "to make ready".
- I was caught off guard and completely unprepared for the exam.
- The company was unprepared for the sudden increase in demand.
- He was unprepared for the harsh winter and froze to death.
- Due to lack of funding, the school was unprepared to deal with the influx of students.
- The government was unprepared for the natural disaster, and it caused a lot of damage.