immobilization vs restrainer

immobilization

noun
  • The act or process of preventing a thing from moving. 

  • The process in which organic soil matter is decomposed and absorbed by microorganisms, and thus not available to plants. 

restrainer

noun
  • Something that restrains 

  • A chemical compound (such as potassium bromide), added to a developer to prevent fogging 

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