efficacious

• His plan of campaign, says General Doubleday, was “simple, efficacious, and should have been successful.” Diverting the attention of Lee, he threw the chief part of his army across the Rappahannock several miles above Fredericksburg; then, marching rapidly to Chancellorsville, he threatened the left flank and rear of the Confederates. —  Abraham Lincoln, Vol. II
• Now in these uncommon cases this means has often also proved highly efficacious, and for this reason, as well as on account of the constant watching against it which is required in war, it is important that it should be clearly explained in theory. —  Clausewitz, ON WAR - Book VI-Chapter 24
• Immersion in a protyle sink is significantly more efficacious, albeit infinitely more perilous. —  FSFMay2005
• By the Chinese it is thought very efficacious, although on what theory it is difficult to understand Entering the city from the north gate, after crossing the ditch that separates the walls from, the French Concession, we find ourselves in close and extremely narrow streets, with shops opening upon them, neither glass nor any partition separating them from passers by. —  The Continental Monthly, Vol. 6, No. 6, December 1864 Devoted To Literature And National Policy
• The sling probably never proved very efficacious, as its accuracy for birds on the wing is too uncertain. —  Short Sketches from Oldest America

Roget's II: The New Thesaurus

Allen's Synonyms and Antonyms

Used in the Same Context