‖n. pl. [ NL., fr. Gr. di- = di`s- twice + &unr_; brother. ] (Bot.) A Linnæan class of plants whose stamens are united into two bodies or bundles by their filaments.

{ } a. [ Cf. F. diadelphe. ] (Bot.) Of or pertaining to the class Diadelphia; having the stamens united into two bodies by their filaments (said of a plant or flower); grouped into two bundles or sets by coalescence of the filaments (said of stamens). [ 1913 Webster ]

n. [ F. diadème, L. diadema, fr. Gr. &unr_;, fr. &unr_; to bind round; dia` through, across + &unr_; to bind; cf. Skr. dā to bind. ] 1. Originally, an ornamental head band or fillet, worn by Eastern monarchs as a badge of royalty; hence (later), also, a crown, in general. “The regal diadem.” Milton. [ 1913 Webster ]

2. Regal power; sovereignty; empire; -- considered as symbolized by the crown. [ 1913 Webster ]

3. (Her.) An arch rising from the rim of a crown (rarely also of a coronet), and uniting with others over its center. [ 1913 Webster ]

Diadem lemur. (Zool.) See Indri. --
Diadem spider (Zool.), the garden spider. [ 1913 Webster ]

v. t. To adorn with a diadem; to crown. [ 1913 Webster ]

Not so, when diadem'd with rays divine. Pope. [ 1913 Webster ]

To terminate the evil,
To diadem the right. R. H. Neale. [ 1913 Webster ]

n. [ Gr. &unr_; a running through; dia` through + &unr_;, used as inf. aor. of &unr_; to run. ] A complete course or vibration; time of vibration, as of a pendulum. [ Obs. ] Locke.