[fahy-fi-nom-uh-non, -nuh n]

noun, plural phi-phe·nom·e·na [fahy-fi-nom-uh-nuh] /ˈfaɪ fɪˌnɒm ə nə/. Psychology.

motion perceived by a subject, especially the illusion of movement produced when stationary stimuli, as pictures or lights, are presented in rapid succession and are sometimes in slightly different positions.

Origin of phi-phenomenon

First recorded in 1925–30 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for phi-phenomenon


noun plural -na (-nə) psychol

the illusion that when two lights are rapidly turned on and off in succession something appears to move backwards and forwards between them while the lights stay stationary
a similar illusion in which one light appears to move smoothly backwards and forwards

Word Origin for phi-phenomenon

C20: arbitrary use of Greek phi
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012