Meat is the currency in West of Loathing. It is acquired as reward from some adventures, found in various places, and by selling items to stores.
Purchasing items from stores requires meat. The prices are fixed, although they can still depend on the store, and you can acquire a basic discount with the Dickerin' perk.
The amount of meat gained from adventures is affected by your Glamour, and can also be modified by different effects and items.