splash lubrication - simple method of lubrication in which a revolving part, such as a gear or a connecting rod, dips into an oil reservoir, such as a crankcase or gear box, and slings the lubricant to other parts of the machine. Surplus oil drips back into the reservoir. Automotive engines, reciprocating compressors, geared drives, chain drives, and reduction gears are examples of equipment lubricated wholly or partly by splash.