lead-footed vs soporific

lead-footed

adj

  • Slow, boring, dull, or stupid. 

  • Tending to drive too fast. 

soporific

adj

  • Boring, dull. 

  • Tending to induce sleep. 

noun

  • Something boring or dull. 

  • Something inducing sleep, especially a drug. 

How often have the words lead-footed and soporific occurred in a corpus of books? (source: Google Ngram Viewer )