Green’s Dictionary of Slang

bread-and-butter adj.

[the blandness of the food]

1. [19C] childish, juvenile, esp. schoolgirlish, often as bread-and-butter miss, a (deliberately) childish young woman.

2. [mid-19C+] plain; thus as n., a plain woman.

3. [mid-19C+] basic, fundamental, quotidian.

SE in slang uses

In phrases

bread and butter fashion (adv.) [the proximity of the bread and butter, which ‘lie on’ each other]

[late 18C–early 19C] describing sexual intercourse.

bread and butter john (n.) [john n.2 (5)]

[1940s] (US Und.) a tramp who begs from house to house.

bread and butter letter (n.) (also bread-and-butter note) [note journalistic jargon bread and nutter column, a column fuelled in the main by press agent handouts and similar varieties of free publicity for those who send it to the writer; such a column harms no one, ‘butters up’ a variety of individuals and keeps the writer off the breadline]

[late 19C+] a letter of thanks sent to one’s host shortly after having enjoyed their hospitality.

bread-and-butter teeth (n.) [large and white, they resemble slices of bread and butter]

[mid-19C; 20C+] buck teeth.

bread and butter warehouse (n.) [? the teas served in its tea rooms or bread and butter fashion ]

[late 18C] Ranelagh Gardens in Chelsea, London, which was built as a pleasure garden in 1741, but gradually fell into disrepute and was shut down in 1803; it is now part of the gardens of the Chelsea Hospital.