Easter Egg
Etymology
The term traces to Atari around 1979–1980, when programmer Warren Robinett secretly hid his name in the game Adventure because Atari refused to credit developers. An executive, Steve Wright, reportedly likened finding such secrets to an Easter egg hunt, and the name stuck. What began as a smuggled signature became a beloved convention across media.
noun phrase · /EE-stur eg/
A hidden message, feature, or joke deliberately tucked inside software, a film, or other media for the curious to find.
What it names
Intentional secrets planted as a reward for attention, distinct from accidental glitches.
Example
Fans discovered an Easter egg in the film — a license plate spelling the director’s birthday.
Related idea
An Easter egg is a hidden feature placed on purpose, the opposite of a bug, which is unwanted behavior nobody intended.