accession vs acquiescence

accession

noun
  • Complicity, concurrence or assent in some action. 

  • A mode of acquiring property, by which the owner of a corporeal substance which receives an addition by growth, or by labor, has a right to the part or thing added, or the improvement (provided the thing is not changed into a different species). 

  • A coming to; the act of acceding and becoming joined. 

  • The act of coming to or reaching a throne, an office, or dignity. 

  • The invasion, approach, or commencement of a disease; a fit or paroxysm. 

  • Access; admittance. 

  • A group of plants of the same species collected at a single location, often held in genebanks. 

  • Agreement. 

  • The act by which one power becomes party to engagements already in force between other powers. 

  • Increase by something added; that which is added; augmentation from without. 

verb
  • To make a record of (additions to a collection). 

acquiescence

noun
  • A silent or passive assent or submission, or a submission with apparent content, distinguished from avowed consent on the one hand, and on the other, from opposition or open discontent; quiet satisfaction. 

  • Inaction, passivity, or neglect to take legal action when it is called for in order to assert, preserve, or safeguard a right, and which inaction implies the abandonment of said right. 

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