Definitions for "Tyndall effect"
Light passing through a colloid is scattered by suspended particles. The light beam becomes clearly visible; this phenomenon is called the Tyndall effect. For example, car headlight beams can be seen in fog, but the beams are invisible in clear air.
the side ways scattering of light passing through a transparent fluid containing suspended material
the phenomenon in which light is scattered by very small particles in its path; it makes a beam of light visible; the scattered light is mainly blue