hyperthyroidism n.

word-forming element meaning "over, above, beyond," and often implying "exceedingly, to excess," from Greek hyper (prep. and adv.) "over, beyond, overmuch, above measure," from PIE root *uper "over."

1690s (in reference to both the cartilage and the gland), from Greek thyreoeides "shield-shaped" (in khondrosthyreoeides "shield-shaped cartilage," used by Galen to describe the "Adam's apple" in the throat), from thyreos "oblong, door-shaped shield" (from thyra "door," from PIE root *dhwer- "door, doorway") + -eides "form, shape" (see -oid). The noun, short for thyroid gland, is recorded from 1849.

word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.