thy·ro·hyoid I. \|thīrō+\adjective alsothy·ro·hyoidean\“+\ Etymology:thyr- + hyoid or hyoid + -an, adjective suffix 1. a.: connecting the thyroid cartilage of the larynx and the hyoid bone b.: of, relating to, or associated with the thyrohyoid muscle 2.: of, relating to, or being the first branchial arch of the vertebrate embryo II. noun : a thyrohyoid part (as a muscle or a nerve)