dif·fer·en·ti·a 
(dĭf′ə-rĕnshē-ə, -shə)
(dĭf′ə-rĕnshē-ə, -shə)n. pl. dif·fer·en·ti·ae (-shē-ē′)
An attribute that distinguishes one entity from another, especially an attribute that distinguishes one species from others of the same genus.
[Latin, difference, from differēns, different-, present participle of differre, to differ; see DIFFER.]