What does COTR stand for?

Cockpit Orientation Trainer - Aviation (NG)

Collared Trogon - Common English name - Scientific name: Trogon Collaris - American Ornithologists Union four-character bird identification (IBP)

Contact Office Technical Representative - National Weather Service

Contracting Officer's Technical Representative - Military technology (DDF)

Cotgrave's Dictionary - A publication (ROG)