This is the 7753rd most frequent Russian word.
идею
"Iдею" means "idea" (accusative case of "идея").
Here, 'идея' is used in its nominative form as the subject of the sentence, referring to a concept or plan.
У меня есть идея, как решить эту проблему.
I have an idea on how to solve this problem.
In this case, 'идею' is in the accusative form as it is the direct object, referring to a specific proposal or thought.
Ты поддержал эту идею на собрании?
Did you support this idea at the meeting?
'Идеей' is in the instrumental form here, as it describes the means by which she shared or what she shared.