advocate vs mainstay

advocate

noun
  • A person who supports others to make their voices heard, or ideally for them to speak up for themselves. 

  • A person who speaks in support of something, or someone. 

  • Someone whose job is to speak for someone's case in a court of law; a counsel. 

  • Anyone who argues the case of another; an intercessor. 

verb
  • To appeal from an inferior court to the Court of Session. 

  • To engage in advocacy. 

  • To call a case before itself for decision. 

  • To encourage support for something. 

  • To plead in favour of; to defend by argument, before a tribunal or the public; to support, vindicate, or recommend publicly. 

mainstay

noun
  • Someone or something that can be depended on to make a regular contribution. 

  • A stabilising rope from the top of the mainmast to the bottom of the foremast. 

  • A chief support. 

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