Under canvas Meaning, Definition & Usage

Definitions
  1. . (a) (Naut.) Moved or propelled by sails; said of any vessel with her sail set, but especially of a steamer using her sails only, as distinguished from one under steam. Under steam and canvas signifies that a vessel is using both means of propulsion. (b) (Mil.) Provided with, or sheltered in, tents.

Webster 1913