These "look-alikes" are frequently confused but have nothing in common except looks. Turgid means "swollen," "overblown," "inflated," "distended," and "pompous": "The candidate then delivered a long, turgid speech." "The stream is turgid because of spring floods." Turbid means "clouded," "not clear," "opaque," "muddy": "The turgid river is turbid (The swollen river is muddy)." "The solution in this test tube is turbid, but it will clear when sediment sinks to the bottom."
Dictionary of problem words and expressions. Harry Shaw. 1975.