descent vs inroad

descent

noun
  • A falling upon or invasion. 

  • A particular extension of the idea of gluing. 

  • A sloping passage or incline. 

  • A drop to a lower status or condition; decline. 

  • Lineage or hereditary derivation. 

  • An instance of descending; act of coming down. 

  • A way down. 

inroad

noun
  • An advance into enemy territory, an attempted invasion; an encroachment, an incursion. 

  • Often followed by in, into, or on: initial progress made toward accomplishing a goal or solving a problem. 

How often have the words descent and inroad occurred in a corpus of books? (source: Google Ngram Viewer )