Yours, Etc.: Origins and Uses of 8 Sign-Offs
mid-13c., from Old French trone (12c.), from Latin thronus, from Greek thronos "elevated seat, chair, throne," from PIE root *dher- (2) "to hold firmly, support" (cf. Latin firmus "firm, steadfast, strong, stable," Sanskrit dharma "statute, law;" see firm (adj.)). Colloquial meaning "toilet" is recorded from 1922.
(Heb. kiss'e), a royal chair or seat of dignity (Deut. 17:18; 2 Sam. 7:13; Ps. 45:6); an elevated seat with a canopy and hangings, which cover it. It denotes the seat of the high priest in 1 Sam. 1:9; 4:13, and of a provincial governor in Neh. 3:7 and Ps. 122:5. The throne of Solomon is described at length in 1 Kings 10:18-20.