interhyal

from The Century Dictionary.

• Situated between or among parts of the hyoid arch of a fish, in relation with the hyomandibular and symplectic bones.
• noun An intermediate osseous or cartilaginous element of the hyoid arch of a fish, connecting its upper and lower parts, in relation with the hyomandibular and symplectic bones; an element connecting the hyomandibular with the branchiostegal arch.

from the GNU version of the Collaborative International Dictionary of English.

• adjective (Anat.) Of or pertaining to a segment sometimes present at the proximal end of the hyoidean arch.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective anatomy Of or pertaining to a segment sometimes present at the proximal end of the hyoid arch.
• noun anatomy An interhyal ligament or cartilage.