English Etymology From ex- + osseous. Adjective exosseous (not comparable) (archaic, literal or figurative) boneless 1650, Thomas Browne, Pseudodoxia Epidemica: […], 2nd edition, London: […] A[braham] Miller, for Edw[ard] Dod and Nath[aniel] Ekins, […], →OCLC:snails, a soft and exosseous animal References “exosseous”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.Wikiwand - on Seamless Wikipedia browsing. On steroids.