Difficult to say; describes something the speaker hesitates to say, often because of tact or awkwardness.
本当のことを言うのは言い辛いが、伝えなければならない。
It's hard to tell the truth, but I have to say it.
その話は友達に言い辛い内容だ。
That's something hard to tell a friend.
上司に給料のことを言うのは言い辛い。
It's difficult to talk to the boss about salary.