MEANING: noun: Cheerfulness; merriment.

ETYMOLOGY: From French hilarité (hilarity), from Latin hilaris (cheerful), from Greek hilaros (cheerful). Earliest documented use: 1568.

XHILARITY - 1. the feeling of having great joy and pleasure and pride at your accomplishments; also, strangely enough, 2. what's left after things aren't funny any more

HILLARITY - plate tectonics

HICLARITY - the false sense that you understand the world, that comes after you've had too much to drink