Wild-eyed (adjective)

1. Having eyes that are wide open and staring, often indicating surprise, fear, or excitement.
2. Appearing crazed or maniacal.

Origin:

Compound word, wild- + eyed, from the old english word "wild" meaning unrestrained, untamed and "eyen" meaning eye.

Examples:

1. The wild-eyed horse reared up in fear.
2. He looked at her wild-eyed, not believing what she had just said.
3. The wild-eyed man ran through the streets shouting.
4. The little girl looked at the clown with wild-eyed wonder.
5. The scientist was wild-eyed with excitement as he explained his new discovery.