Dictionary.com
Thesaurus.com

baking sheet vs. cookie sheet

[bey-king sheet] / ˈbeɪ kɪŋ ˌʃit /

noun

  1. a flat, rectangular metal pan used for baking cookies, bread, and other food in an oven, typically having four slightly raised rims.

[kook-ee sheet] / ˈkʊk i ˌʃit /

noun

  1. a flat, rectangular pan used for baking cookies or biscuits, typically having one or two slightly raised rims.