'Bullion' definitions:

Definition of 'bullion'

noun

A mass of precious metal

noun

Gold or silver in bars or ingots

From: GCIDE

Bullion \Bul"lion\ (b[.u]l"y[u^]n), n. [Cf. OE. bullyon a hook used for fastening the dress, a button, stud, an embossed ornament of various kinds, e. g., on the cover of a book, on bridles or poitrels, for purses, for breeches and doublets, LL. bullio the swelling of boiling water, a mass of gold or silver, fr. L. bulla boss, stud, bubble (see Bull an edict), or perh. corrupted fr. F. billon base coin, LL. billio bullion. Cf. Billon, Billet a stick.]
1. Uncoined gold or silver in the mass. [1913 Webster]
Note: Properly, the precious metals are called bullion, when smelted and not perfectly refined, or when refined, but in bars, ingots or in any form uncoined, as in plate. The word is often often used to denote gold and silver, both coined and uncoined, when reckoned by weight and in mass, including especially foreign, or uncurrent, coin. [1913 Webster]
2. Base or uncurrent coin. [Obs.] [1913 Webster]
And those which eld's strict doom did disallow, And damm for bullion, go for current now. --Sylvester. [1913 Webster]
3. Showy metallic ornament, as of gold, silver, or copper, on bridles, saddles, etc. [Obs.] [1913 Webster]
The clasps and bullions were worth a thousand pound. --Skelton. [1913 Webster]
4. Heavy twisted fringe, made of fine gold or silver wire and used for epaulets; also, any heavy twisted fringe whose cords are prominent. [1913 Webster]