This is the 11792nd most frequent Spanish word.
guisante
Pea.
Here, 'guisante' is used as a noun to refer to the vegetable.
El guisante es una legumbre pequeña y redonda.
The pea is a small and round legume.
In this case, 'guisantes' is plural to indicate more than one.
Compré un kilo de guisantes frescos en el mercado.
I bought a kilogram of fresh peas at the market.
Here, 'guisantes' is used as an ingredient in the context of cooking.