What does the word smooth mean?

Usage examples for smooth

  1. As I have said, his companion was a much smaller man, with a smooth, almost boyish face, a pair of twinkling eyes, but a mouth rather hard set. – My Strangest Case by Guy Boothby
  2. Over broken ground it was impossible that he could hope to do more than seven miles an hour- less on bad parts, more on the smooth. – The Green Flag by Arthur Conan Doyle
  3. Ahead, the road apparently ran quite straight and smooth for a considerable distance. – The Mad King by Edgar Rice Burroughs