Stroke

noun

1. An act of stroking (moving one's hand over a surface).

   "She gave the cat a stroke."

2. A blow or hit.

   "a stroke on the chin"

3. A single movement with a tool.
4. One of a series of beats or movements against a resisting medium, by means of which movement through or upon it is accomplished.

   "the stroke of a bird's wing in flying, or of an oar in rowing"

5. A powerful or sudden effort by which something is done, produced, or accomplished; also, something done or accomplished by such an effort.

   "a stroke of genius; a stroke of business; a master stroke of policy"