A variable or factor that confuses the results of a study by affecting both the cause and effect; something that bewilders or confuses.
From confound + -er suffix. Originated as a general word for 'one who confuses,' but became a technical term in statistics and research methodology.
In medical research, a 'confounder' is a sneaky variable—if you study whether coffee causes heart disease but coffee-drinkers also smoke more, smoking is the confounder that's actually causing the problem, not the coffee.
Complete word intelligence in one call. Free tier — 50 lookups/day.