1. Pertaining to, caused by, exhibiting, showing, having, or resulting from shared feelings, pity, generosity,, understanding, or compassion: Stella's sister was very sympathetic when her favourite kitten was run over by a car in the street in front of their home.
2. Concerning something that is agreeably suited to one's disposition, tastes, or mood; congenial: The couple was extremely happy by living in such sympathetic surroundings with wonderful neighbours.

1. A sympathetic nerve or the sympathetic nervous system is a set or series of interconnected or interdependent parts of entities, objects, organs, or organisms that function together in a common purpose or produce results impossible of achievement by one of them acting or operating alone.
2. A part of the nervous system which serves to accelerate the heart rate, to constrict blood vessels, and to raise blood pressure.

The sympathetic nervous system and the parasympathetic nervous system are parts of the autonomic nervous system.

A severe, bilateral uveitis that starts as an inflammation of the uveal tract of one eye: Sympathetic uveitis can result from a puncture wound.

The injured eye is termed the "exciting eye". If the affected area is not removed within ten days of the accident that caused the wound, blindness will occur.