sol·i·dar·i·ty 
(sŏl′ĭ-dărĭ-tē)
(sŏl′ĭ-dărĭ-tē)n.
Unity of purpose, interest, or sympathy: People gathered to show solidarity with the earthquake victims.
[French solidarité, from solidaire, interdependent, from Old French, in common, from Latin solidus, solid, whole; see SOLID.]