unprepared
🇺🇸
/ˌʌnprɪˈperd/
🇬🇧
/ˌʌnprɪˈpeəd/
not having made necessary preparations or arrangements
He was unprepared for the interview and couldn't answer the questions.
not having the necessary knowledge, skills, or resources to do something
The team was unprepared for the challenges they faced.