Since this word has okurigana (hiragana attached to the kanji) you know that it's probably going to be the kun'yomi reading. You learned this with its intransitive pair verb 退く, but here's a mnemonic just in case:
Remember the re-zoner? Well, to repel bad luck, she, re-zoned (しりぞ) the whole place. No bad luck allowed inside the zone.
This charm has the power to repel misfortune.
The council dismissed all of the proposals.
It's hard for Japan to reject the opinions of the U.S.