na-adjective
extremely weird; very eccentric
Emphatic expression for something bizarre or outlandish; stronger than 奇妙 alone.
彼のファッションは奇妙奇天烈で、誰も真似できない。
His fashion is extremely weird, and no one can imitate it.
その映画のストーリーは奇妙奇天烈だった。
The story of that movie was very eccentric.
Compound of 奇妙 (strange) and 奇天烈 (very strange), both ateji. The exact origin of 奇天烈 is uncertain, but it likely arose as an emphatic reduplicative-like formation.