noun
Refers to a state where a decision has not yet been made; often used in formal or official contexts.
その問題はまだ不決定のままだ。
The issue remains undecided.
不決定事項は次回の会議で話し合います。
Pending matters will be discussed at the next meeting.
未定 is a more everyday word for 'undecided' or 'not yet fixed'; 不決定 is more formal and less common.
Compound of 不 (negative prefix) and 決定 (decision). The exact historical derivation is uncertain, but the word follows a standard Sino-Japanese pattern for forming abstract nouns.