英语词源字典 - 在线词源网站

diadem [diadem 词源字典]: diadem: [13] A diadem was originally something that was bound round someone’s head. The word comes, via Old French diademe and Latin diadēma, from Greek diádēma; this was a derivative of diadein, a compound verb formed from the prefix dia- ‘across’ and dein ‘bind’. In Greek it was often applied specifically to the regal headband worn by Alexander the Great and his successors.
[diadem etymology, diadem origin, 英语词源]
diadem (n.): late 13c., from Old French diademe and directly from Latin diadema "cloth band worn around the head as a sign of royalty," from Greek diadema, from diadein "to bind across," from dia- "across" (see dia-) + dein "to bind," related to desmos "band," from PIE *de- "to bind." Used of the headband worn by Persian kings and adopted by Alexander the Great and his successors.
hendiadys (n.): 1580s, figure of speech in which two nouns joined by and are used in place of a noun and an adjective; from Medieval Latin alteration of Greek hen dia duoin "one (thing) by means of two." If this term was used by Greek grammarians it is no longer found in their writings, but it is frequent among Latin writers.
diadelphous: "(Of stamens) united by their filaments so as to form two groups", Early 19th century: from di-¹ 'two' + Greek adelphos 'brother' + -ous.