The state in which a series of repeated actions have an effect greater than the sum of their individual effects; noted especially in the repeated administration of drugs or repeated consumption of trace elements or chemicals that show no immediate effect.

plural of sound effect

To become enforceable, or applicable.

Operating or functioning; in force; in play.

For all practical purposes; in practice; actually; essentially; basically.

An accelerating growth of magnitude, including fame, fortune, importance, or danger.

The circumstance in which one event instigates an expansive set of other events.

(quantum mechanics) An effect marked by the quantization of the Hall resistance, observed in two-dimensional electron systems subjected to low temperatures and strong magnetic field.

(medicine, statistics) A skewing of data in randomized medical studies that occurs when healthy participants are less likely to drop out of the study than sicker patients.

(idiomatic) with a symbol, usually an effigy, substituted for a real person or thing.