acoelomate

acoe·lo·mate

noun \(ˈ)ā-ˈsē-lə-ˌmāt\

Definition of ACOELOMATE

: an invertebrate lacking a coelom; especially : one belonging to the group comprising the flatworms and nemerteans (class Nemertea or Nemertinea) and characterized by bilateral symmetry and a digestive cavity that is the only internal cavity

—acoelomate adjective