This is the 3110th most frequent Japanese word.
保留
"保留" means "reservation," "hold," or "pending."
In this sentence, "保留" is used in the sense of deferring or postponing a decision regarding something mentioned, here the suggestion.
会議で彼の提案が保留された。
His suggestion was put on hold during the meeting.
Here, "保留" refers to the act of putting a call on hold, commonly used in telecommunications.
保留ボタンを押してお待ちください。
Please press the hold button and wait.
"保留" indicates that an action, such as his promotion, is temporarily delayed pending certain conditions.