Quick Definition
a head-wreath, crown
Strong's Definition
a "diadem" (as bound about the head)
Derivation: from a compound of G1223 (διά) and G1210 (δέω);
KJV Usage: crown
Thayer's Greek Lexicon
διάδημα, διαδήματος, τό (διαδέω, to bind round), a diadem, i. e. the blue band marked with white with which Persian kings used to bind on the turban or tiara; the kingly ornament for the head: Rev_12:3; Rev_13:1; Rev_19:12. (Xenophon, Cyril 8, 3, 13; Est_1:11; Est_2:17 for λΖΜϊΖψ; 1Ma_1:9.) [SYNONYMS: διάδημα στέφανος: στέφανος, like the Latincorona, is a crown in the sense of a chaplet, wreath, or garland the badge of victory in the games, of civic worth, of military valor, of nuptial joy, of festal gladness ; διάδημα is a crown as the badge of royalty, βασιλείας γνώρισμα (Lucian, Pisc. 35). Cf. Trench, § xxiii.; Lightfoot on Php_4:1; Dict. of Christ. Antiq. under the word Coronation, p. 464f; B. D. American edition under the word ; but cf. στέφανος, a.]
Mounce Concise Greek Dictionary
διάδημα diadēma 3x
pr. a band or fillet; a diadem, the badge of a sovereign, Rev_12:3 ; Rev_13:1 ; Rev_19:12
Abbott-Smith Greek Lexicon
διάδημα , -τος , τό
( < διαδέω , to bind round),
[in LXX for H3804 (as Ezr_1:11 ), etc.;]
the band round the τιάρα of a Persian king; a diadem, the badge of royalty: Rev_12:3 ; Rev_13:1 ; Rev_19:12 .†
SYN.: στέφανος G4735 , the badge of " victory, of valour, of nuptial joy, of festal gladness " (but v. M , Th ., i, 219; cf. DB , i, 530, 604).
Liddell-Scott — Intermediate Greek Lexicon
διάδημα διάδημα, ατος, τό, [Etym: διαδέω] "a band or fillet": esp. "the band round the" τιάρα of the Persian king, Xen.
STEPBible — Tyndale Abridged Greek Lexicon
διάδημα, -τος, τό
(διαδέω, to bind round), [in LXX for כֶּתֶר (as Est.1:11), etc. ;]
the band round the τιάρα of a Persian king; a diadem, the badge of royalty: Rev.12:3 13:1 19:12.†
SYN.: στέφανος, the badge of "victory, of valour, of nuptial joy, of festal gladness " (but see M, Th., i, 219; cf. DB, i, 530, 604). (AS)