The most common and most likely answer to this crossword clue is the 9 letter word BENIGHTED
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More clues leading to the result BENIGHTED
Buddy explains!

The straight part
We know that "Ignorant" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case ignorant = benighted.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does BENIGHTED mean?
BENIGHTED verb- (chiefly in passive) To overtake (a traveller etc) with the darkness of night, especially before shelter is reached.
- To darken; to shroud or obscure.
- To plunge or be overwhelmed in moral or intellectual darkness.
- Overtaken by night; especially of a traveller, etc.: caught out by oncoming night before reaching one's destination.
- Plunged into darkness.
- Lacking education or knowledge; unenlightened; also, lacking morality; immoral, unscrupulous.
- Difficult to understand; abstruse, obscure.