Sentence:  Through 1911 and 1912 , as the Cubist <WSD>facet-plane</WSD> 's tendency to adhere to the literal surface became harder and harder to deny , the task of keeping the surface at arm's length fell all the more to eye-undeceiving contrivances . 
Meaning of the word marked with <WSD> tags:  the plane of a facet of an object (as of a cube)