The term 'kind of grease' can be solved by two crossword solutions: AXLE (4 letters) and ELBOW (5 letters). Grease is a lubricant used to reduce friction between two surfaces. It is often used in automotive applications, such as on axles and elbows, to reduce wear and tear on the parts. Grease is also used in industrial settings, such as in bearings and other moving parts. Grease is available in a variety of types, including mineral oil-based, synthetic, and biodegradable.