lud-, ludi-, lus- +

1. The doctrine stating that the material world is an immaterial product of the senses.
2. The use of illusionary devices and techniques in art or decoration

1. One who produces illusions; specifically, a conjuror or sleight-of-hand performer.
2. An adherent of the doctrine of illusionism.

That which tends to illude or deceive by unreal appearances; productive of illusion or false impressions; deceptive; illusory.

Produced by, based on, or having the nature of an illusion (mistaken perception of reality).

A world without color appears to be missing crucial elements

Colors not only enable us to see the world more precisely, they also create emergent qualities that would not exist without them.

Many people believe that color is a defining and essential property of objects, one depending entirely on the specific wavelengths of light reflected from them.

• Color is a sensation created in the brain.
• If the colors we perceived depended only on the wavelength of reflected light, an object's color would appear to change dramatically with variations in illumination throughout the day and in shadows.
• Instead, patterns of activity in the brain render an object's color relatively stable despite changes in its environment.
• The pathway in the brain that serves navigation and movement is essentially color-blind.
• People who become color-blind after a stroke appear to have normal visual perception otherwise.
• The study of illusory colors (colors that the brain is tricked into seeing) demonstrates that color processing in the brain occurs hand in hand with processing of other properties; such as, shape and boundary.
• Visual perception begins with the absorption of light; or, more precisely, the absorption of discrete packets of energy called photons; by the cones and rods located in the retinas of the eyes.
• A cone photoreceptor responds according to the number of photons it captures, and its response is transmitted to two different types of neurons, termed on and off bipolar cells.
• These neurons in turn provide input to on and off ganglion cells that sit side by side in the retina.
• About 40 percent or more of the human brain is thought to be involved in vision.
• Visual signals disperse to more than 30 different areas, interconnected by more than 300 circuits.
• The complexity of color illusion suggests that it is unlikely to result from a single unitary process, but may represent an attempt by the brain to reconcile competing signals from multiple specialized pathways.
• The study of illusory colors demonstrates that the perception of color in the brain generates emergent properties of form and depth.
• Ongoing research about illusory colors will continue to offer a tantalizing portal into the complexities of the human visual system.

1. A dramatic or mimic representation, usually of a light or humorous character, such as was commonly introduced between the acts of the long mystery-plays or moralities, or exhibited as part of an elaborate entertainment; hence (in ordinary about the 17-18th century use) a stage-play; especially, of a popular nature, a comedy, or a farce.
2. An interval in the performance of a play; the pause between the acts, or the means (dramatic or musical) employed to fill this pause.
3. Etymology: from Middle Latin interludium, "an interlude"; from Latin inter-, "between" + ludus, "a play". Originally, farcical episodes introduced between acts of mystery plays.

Playful.

Making fun of.

Playfulness.

1. In psychiatry; unreal, playlike, quasi, pseudo.

Ludic activity: Higher animals have a quantity of energy left after performing all the movements required by their physiological life processes. This excess energy is usually expended (witout purpose) in some way most usually in play activity, called "ludic activity".

2. Of or pertaining to undirected and spontaneously playful behavior.

Ludicrous and pathetic.

1. So obviously absurd or incongruous as to be laughable.
2. Ludicrous can describe either something funny that provokes laughter, or something ridiculous and laughable, not worthy of serious consideration.
3. Causing derisive laughter because something is so amusingly absurd, utterly ridiculous, incongruous, foolish, abnormally unreasonable, and wholly unsuitable for a situation.

Ludicrous was borrowed from Latin ludicrus, from ludicrum, "joke, amusement", and from ludere, "to play". The current sense of causing derisive laughter, ridiculous, is first recorded in English in 1782, in Frances Burney's Cecilia.

1. A reference to being broadly or extravagantly humorous; resembling a farce: "She was ludicrous with her green and red hair."
2. Completely devoid of wisdom or good sense.

A deception or mocking.

In Roman antiquity, ludi publici (LYOO digh PUB li sigh) were public games and spectacles, including athletic competitions, horse and chariot races, exhibitions of the arena, and theater.

Ludi Cercenses (sur SEN seez) were games of the Circus; ludi scenici (SEN i sigh) of the theater.

Some were named for particular festivals: ludi Apollinares (uh pol" i NAY reez), in honor of Apollo, chiefly theatrical; ludi Romani (roh MAY nigh), in honor of Jupiter, in September; and ludi Megalenses (meg" uh LEN seez), in honor of the Magna Mater, April 4 to April 10.

1. A game, played with dice and counters on a special board.
2. A kind of simple play.