Maniacal (adjective)

Wildly or uncontrollably enthusiastic or obsessed; crazy or insane; characterized by uncontrolled excitement or emotion.

Origin:

Maniacal: derived from the noun 'maniac', which comes from latin mania meaning 'insanity, madness'.

Examples:

1. The young girl's maniacal laughter could be heard from the next room.
2. He had a maniacal look in his eyes as he spoke about his new project.
3. The detective pursued the case with a maniacal determination, working long hours and following every lead.
4. She was manic in her pursuit of success, working tirelessly and neglecting her health and relationships.
5. His maniacal laughter echoed through the empty streets as he ran down the sidewalk.