The Collaborative International Dictionary
Hyperthyrion
Hyperthyrion \Hy`per*thyr"i*on\, n. [NL., fr. Gr. ?; "ype`r over + ? door.] (Arch.) That part of the architrave which is over a door or window.
Wiktionary
hyperthyrion
n. (context architecture English) That part of the architrave which is over a door or window.