to lift and give support to something by putting something under it

He was sitting upright in his hospital bed, propped up by pillows. 他靠着枕头，直挺挺地坐在医院的病床上。

There were the usual bunch of drinkers propped up at (= leaning against) the bar. 有一群常客倚靠在吧台上。

to give support to something, especially a country or organization, so that it can continue to exist in a difficult situation

How long is the government likely to survive without the US military force there to prop it up? 没有美国的军事力量在那里支撑，那个政府还能维持多久？