inarticulate
adj. US //ˌɪnɑɹˈtɪkjəɫət// UK //ɪnɑːtˈɪkjʊlˌeɪt// inar·tic·u·late
From Latin inarticulatus and from in- + articulate. See -ate (adjective-forming suffix).
From the substantivation of the above adjective through the associated taxon's name (Inarticulata). Used by contrast with Articulata.