to watch with folded arms (idiom); to look on without lifting a finger
Definitions (粵典–words.hk)
動詞
淨係喺隔籬睇，唔出手，唔幫手，唔干涉 to sit back and watch; to stand by indifferently; literally: to put the hands in one's sleeves and look on
如果你見到我暈咗，你唔會袖手旁觀啩！
如果你见到我晕咗，你唔会袖手旁观啩！
jyu4 gwo2 nei5 gin3 dou2 ngo5 wan4 zo2, nei5 m4 wui5 zau6 sau2 pong4 gun1 gwaa3! If you see me faint, you won't sit back and watch, right?
近義詞
食花生
Definitions (Wiktionary)
phrase, idiomatic
to put one's hands into one's sleeves and look on; to observe and do nothing; to stand by; to become a passive observer
Definitions (Kaifangcidian)
（沒有對應漢語詞彙）
Definitions (HSK3.0)
HSK3 七一九级词汇表 #4680
Examples (Tatoeba—Mandarin-English)
Mandarin
你要是不答应的话，我就袖手旁观。
你要是不答應的話，我就袖手旁觀。
nǐ yào shi bù dā ying de huà ， wǒ jiù xiù shǒu páng guān 。
If you don't make the promise, then I'll just stand by and watch.
Mandarin
只要好人袖手旁观，恶人就会得胜。
只要好人袖手旁觀，惡人就會得勝。
zhǐ yào hǎo rén xiù shǒu páng guān ， è rén jiù huì dé shèng 。
As long as good people do nothing, evil will triumph.
Mandarin
她什么也不做，只是袖手旁观。
她什麼也不做，只是袖手旁觀。
tā shén me yě bù zuò ， zhǐ shì xiù shǒu páng guān 。