alone vs secret

alone

adj
  • By oneself, solitary. 

  • Lacking peers who share one's beliefs, experiences, practices, etc. 

adv
  • Not requiring anything further; merely. 

  • By oneself; apart from, or exclusive of, others; solo. 

  • Without outside help. 

  • Used to emphasize the size or extent of something by selecting a subset. 

  • Not permitting anything further; exclusively. 

secret

adj
  • Being or kept hidden. 

noun
  • Private seclusion. 

  • A piece of knowledge that is hidden and intended to be kept hidden. 

  • The key or principle by which something is made clear; the knack. 

  • A form of steel skullcap. 

  • Something not understood or known. 

  • Any prayer spoken inaudibly and not aloud; especially, one of the prayers in the Tridentine Mass, immediately following the "orate, fratres", said inaudibly by the celebrant. 

verb
  • To make or keep secret. 

  • To hide secretly. 

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