sym·pa·thy 
(sĭmpə-thē)
(sĭmpə-thē)n. pl. sym·pa·thies
1.
a. A feeling of pity or sorrow for the distress of another; commiseration. See Synonyms at pity.
b. often sympathies An expression of such feeling: offered her sympathies to the mourning family.
2.
a. Mutual understanding or feeling between people: "Like two frightened children, we sought at the same time to comfort one another, so quick was the sympathy between us" (Nicholas Meyer).
b. Agreement with or support for an opinion or position: The mayor is in sympathy with the proposal.
c. often sympathies A tendency to support a position or opinion: a politician of conservative sympathies.
3.
a. A relationship or affinity between things in which whatever affects one correspondingly affects the other: "Continuous measurements of ionospheric densities ... showed a variation of noon ionization in sympathy with sunspot activity" (E.V. Appelton).
b. Physics A relation between bodies such that vibrations in one body cause sympathetic vibrations in another.
c. Physiology A relation between parts or organs by which a disease or disorder in one induces an effect in the other.
[Latin sympathīa, natural affinity, fellow feeling, from Greek sumpatheia, from sumpathēs, affected by like feelings : sun-, syn- + pathos, emotion; see kwent(h)- in the Appendix of Indo-European roots.]