颠簸着前进 meaning in Chinese

bumvi

The chair chuffed slowly up the incline , rocking and jolting on the frozen clods . and suddenly , on the left , came a clearing where there was nothing but a ravel of dead bracken , a thin and spindly sapling leaning here and there , big sawn stumps , showing their tops and their grasping roots , lifeless . and patches of blackness where the woodmen had burned the brushwood and rubbish
小车子馒慢地驶上斜坡，在冰陈了的泥块上颠簸着前进，忽然左边现出一块空地，是儿只有一丛枯稿了的蕨草，四下杂布着一些斜倾的细长的小树，几根锯断了的大树桩，毫无生气地露着顶和根还有几处乌黑的地方，那是樵夫们焚烧树枝乱草和废物过后的痕迹。