What does the word efficacious mean?

Usage examples for efficacious

  1. One touch of danger is almost as efficacious as one touch of nature. – The Honorable Peter Stirling and What People Thought of Him by Paul Leicester Ford
  2. Then by Jove I'll see if it will prove equally efficacious here. – The Voyage of the Aurora by Harry Collingwood
  3. This treatment is always efficacious, as you are absolutely sure of getting what is necessary for the land. – Making a Lawn by Luke Joseph Doogue