n. The slender lemur of Ceylon, Arachnocebus or Loris gracilis, a prosimian mammal of the family Lemuridæ and subfamily Nycticebinæ: more fully called slender loris. Also lori; pl. loris.n. [capitalized] The typical genus of Lorisinæ, based by Geoffroy on the slender lori or loris of Ceylon, and the same as Arachmocebus of Lesson; extended to include the slow lemur, which is more frequently referred to a genus Nycticebus, Stenops, or Bradylemur.