(sciences) A side effect, especially a positive one in pharmacology.

(aerospace) The concept that the most efficient place for spacecraft to change velocity is at the periapsis (the lowest point of an orbit).

(physics) A phenomenon that occurs when an electric current passes through an anisotropic crystal.

(music) (preceded by definite article) A vocal effect produced when the entire lyrics of a song are processed through an auto-tune system.

plural of Werther effect

The effect of mass media deterring people from suicide by promoting alternatives.

plural of Papageno effect

An effect that changes or produces birefringence in an optical medium induced by electric field.

The transcendental change of perception when one can view the Earth, or any other planetary object, within the universal context.

plural of spotlight effect