Sentence:  The western sky is wallen / With shadowy mountains, built upon the marge / Of the horizon, from eve's purple sheen, / And thin gray clouds, that daringly <WSD>uplean</WSD> / Their silver cones upon the crimson verge / Of the high zenith, 
Meaning of the word marked with <WSD> tags:  To lean or incline upward; to cause (something) to lean upward.