Committee
noun
There are member(s) of a committee (委員) all getting together to meet. This is the committee itself.
いいんかい
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well. Of course it will help to know 委員 as well, since it's 2/3rds of the word.
いい加減、委員会での重要な問題に対して意見をころころ変えるのをやめてくれないか。みんなにいい迷惑だよ。
You should stop flip-flopping on important issues in the committee, it’s irresponsible. Everyone finds it annoying.