at disposal vs expendable

at disposal

expendable

noun
  • An expendable person or object; usually used in the plural. 

adj
  • Designed for a single use; not reusable. 

  • Not essential or mandatory in order to achieve a goal. 

  • Regarded as not worth preserving or saving; able to be sacrificed. 

  • Able to be expended; not inexhaustible. 

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