The term 'grease-filled' can be summarized by the word 'OILY, ' which is a four-letter word. Grease-filled refers to something that is filled with a thick, OILY substance, usually used as a lubricant or sealant. It is often used in automotive and industrial applications, such as in engines, bearings, and other moving parts. Grease-filled items are also used in cooking, such as in frying pans and baking dishes.