English word loony comes from Latin -ticus, Latin luna, and later English lunatic (An insane person. Crazed, mad, insane, demented.)
| Dictionary entry | Language | Definition |
|---|---|---|
| -ticus | Latin (lat) | |
| luna | Latin (lat) | (figuratively) a month. (figuratively) a night. A crescent shape. The Moon. |
| lunaticus | Latin (lat) | Of, or living on, the moon. Epileptic, lunatic, moonstruck, crazy. |
| lunatic | English (en) | An insane person. Crazed, mad, insane, demented. |
| lunacy | English (en) | (of a person or group of people) The state of being mad, insanity. Something deeply misguided.. A cyclical mental disease, apparently linked to the lunar phases. Insanity implying legal irresponsibility. |
| loony | English (en) | (of a person) Insane.. (of a thing) Very silly, absurd. An insane or very foolish person. |