'angulosplenial' originates from Modern Latin anatomical formation, combining Latin 'angulus' ('angle') via the combining form 'angulo-' with 'splenial', from Greek 'splēníon' ('bandage; strap-like'), referring to the slender shape of the bone.

'Angulosplenial' entered English scientific usage in the 19th–20th centuries from anatomical Latin as a descriptive compound and has been used in vertebrate morphology without significant orthographic change.

Initially, it denoted the mandibular element formed by fusion of the angular and splenial bones, and this technical meaning has remained stable in modern usage.