promising vs trustful

promising

adj

  • Encouraging and inspiring confidence. 

  • Showing promise, and likely to develop in a desirable fashion. 

  • a promising young apprentice 

noun

  • The act of making a promise. 

trustful

adj

  • Trusting; willing to trust. 

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