Sentence:  All her energy was devoted to the <WSD>amassment</WSD> of a vast fortune. 
Meaning of the word marked with <WSD> tags:  The act of amassing.<ref>(Edward Phillips), "(The New World of English Words)," London: Nath. Brooke, 1658: “"Amassement," (...) a crouding, or heaping of several things together.”[http://name.umdl.umich.edu/A54746.0001.001]</ref><ref>(Elisha Coles), "An English Dictionary," London: Peter Parker, 1677: “"Amassement," (...) heaping up.”[http://name.umdl.umich.edu/A33754.0001.001]</ref>