What's the difference between precipitate and turbidity?
My understanding is that turbidity is an adjective describing the presence or degree of particulate matter suspended in a liquid (see turbidimetry), whereas a precipitate is a particulate that can result in turbidity.

The turbidity generated by a precipitate is a function of its ability to form a stable suspension. If the precipitate simply drops to the bottom of a container or readily flocculates, the resultant turbidity will be low. The turbidity of a suspension is also going to be a function of the solvent and the nature and concentration of dissolved ions - a dramatic example of this is the rapid clarification of muddy freshwater at river deltas mixing with salt water.

If the word turbidity is being used as a noun, it is probably referring to a light-occluding suspension.