Green’s Dictionary of Slang

tommy n.2

[orig. milit. jargon tommy, the bread supplied as part of rations. This in turn had evolved from orig. 18C brown george to brown tommy to tommy brown and thence to its abbr. Note that St Thomas’ Day, on which bread was distributed by charities, preceded the milit. coinage]

1. [late 18C–1930s] (a loaf of) bread.

2. [mid-19C–1940s] solid food in general.

3. [late 19C+] (Aus./N.Z.) bread baked with sugar and currants.

In compounds

tommy and exes (n.)

[late 19C–1900s] bread, beer and tobacco.

tommy shop (n.)

1. [early-late 19C] a food shop owned by an employer, who issues his workers vouchers, which can only be used at that shop; thus attrib. Tommy (shop) system, Tommy shopkeeper.

2. [mid-19C] a bakery.

tommy truck (n.)

[late 19C] a conveyance bringing food to workmen.

In phrases

brown tommy (n.)

[late 18C–19C] brown bread.

soft tommy (n.)

[late 18C–19C] white bread.

In exclamations

that’s the tommy!

[late 19C] that’s right!