Definition of mechanical:

• Constructed according to the principles of mechanics; applying to machines; acting as a mere machine: done in the manner of a machine, or by force of mere habit; pertaining to artisans or mechanics: acting by physical power, without chemical change. Mechanical philosophy, a philosophy which would account for things on the principles of mere mechanics. Mechanical powers, the lever, the wheel and axle, the pulley, the inclined plane, the wedge, and the screw, the elementary contrivances of which all machines are composed.
• Pert. to machines; constructed or performed according to the laws of mechanics; physical, or not chemical; manual, or not mental; done by a machine; done by mere force of habit.

Usage examples for mechanical

1. With a mechanical instinct she turned in at the door of her mother's house.  An Isle in the Water by Katharine Tynan

2. Among the presents that were carried out for the Emperor were an apparatus for the air pump, various articles for conducting a set of experiments in electricity, and the models of a complete set of mechanical powers placed upon a brass pillar.  Travels in China, Containing Descriptions, Observations, and Comparisons, Made and Collected in the Course of a Short Residence at the Imperial Palace of Yuen-Min-Yuen, and on a Subsequent Journey through the Country from Pekin to Canton by John Barrow

3. The old count sat low in his saddle and urged his horse with a mechanical jerk of the heels.  The Isle of Unrest by Henry Seton Merriman

4. March waited with a sort of mechanical expectation of his gratitude for the work put in his way, but nothing of the kind came from Lindau, and March was left to say, Well, everything is understood, then; and I don't know that I need add that if you ever want any little advance on the work- I will ask you, said Lindau, quietly, and I thank you for that.  A Hazard of New Fortunes by William Dean Howells