demand vs must

demand

noun
  • A requirement. 

  • An urgent request. 

  • The desire to purchase goods and services. 

  • An order. 

  • The amount of a good or service that consumers are willing to buy at a particular price. 

  • A forceful claim for something. 

  • More precisely peak demand or peak load, a measure of the maximum power load of a utility's customer over a short period of time; the power load integrated over a specified time interval. 

verb
  • To require of someone. 

  • To claim a right to something. 

  • To ask forcefully for information. 

  • To request forcefully. 

  • To issue a summons to court. 

must

noun
  • Something that is mandatory or required. 

  • Something that exhibits the property of being stale or musty. 

  • The property of being stale or musty. 

  • Fruit juice that will ferment or has fermented, usually from grapes. 

verb
  • To do as a requirement; indicates that the sentence subject is required as an imperative or directive to execute the sentence predicate, with failure to do so resulting in a failure or negative consequence. 

  • To become musty. 

  • Used to indicate that something that is very likely, probable, or certain to be true. 

  • To do with certainty; indicates that the speaker is certain that the subject will have executed the predicate. 

  • To make musty. 

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