Green’s Dictionary of Slang

beans n.3

also bean time
[1940s+] (US)

1. food.

2. a mealtime.

SE in slang uses

In phrases

full of beans (adj.) [horseracing jargon, referring to a sprightly horse]

1. [mid-19C+] arrogant, esp. through the sudden or recent acquiring of wealth.

2. [mid-19C+] (also full of oats) enthusiastic, excited, cheerful.

3. [1930s+] (US) nonsensical, rubbishy.

know beans (v.) (also know beans when the bag is open, …untied) [abbr. know how many (blue) beans make five ]

[mid-19C–1910s] (US) to be well aware, to be knowledgeable; often in negative.

know how many (blue) beans make five (v.)

[late 18C+] to be alert, to be aware of facts or information.

like beans (adv.) (also as fast as beans, like beans in Boston)

[mid–late 19C] energetically, very fast.

not know beans (v.)

[1960s] to be ignorant.

some beans (adj.)

[mid-19C] (US) impressive, of some account.