A "silicon spatula" refers to a cooking utensil made from a material called silicone. It is used for stirring, mixing, flipping, and scraping food while cooking, and can withstand high heat. Full definition
Remove caramel from the heat, add pieces of salted butter (a) and stir with silicon spatula until combined. (bake-no-fake.com)
When you bake a lot, you'll understand the importance of having a good - quality silicon spatula to scrape the batter from the mixing bowl into the baking pan. (dishbydish.net)
Cook over low heat, stirring constantly and scraping the bottom with silicon spatula or wooden utensil. (andcuriously.net)