the medical condition of apoplexy in the brain, i.e. my grandfather had a stroke and now he cannot speak, the translation is: apoplejÃa OR derrame cerebral.
the act of petting or other acts of light touching, i.e. I stroked the cat's fur, the translation is: acariciar.
the act of moving a brush across a canvas, i.e. The calligrapher created the Chinese character in five strokes, the translation is: pincelada. (If a writer is using a pen or pencil, then the proper word is: trazo.)
the act pushing water or other liquid with your arm (usually in swimming or rowing), i.e. the swimmer had a strong stroke, pushing him forward, the translation is: braceo OR brazada.