bolstering vs pillar

bolstering

noun
  • The act by which something is bolstered; support. 

pillar

noun
  • An essential part of something that provides support. 

  • A portable ornamental column, formerly carried before a cardinal, as emblematic of his support to the church. 

  • A large post, often used as supporting architecture. 

  • The centre of the volta, ring, or manege ground, around which a horse turns. 

  • The body from the hips over the core to the shoulders. 

  • Something resembling such a structure. 

verb
  • To provide with pillars or added strength as if from pillars. 

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