Definitions

1. verb

to take something out of a rack, especially a book from a bookshelf

“The student unrailed the book from the rack to show her friend.”

2. verb

to remove the racks or supports from a vehicle, especially a bicycle or a trailer

“The cyclist had to unrack his bicycle to transport it in the car.”

3. noun

an act of removing a rack or supports from a vehicle

“The unracling of the bicycle took a lot of effort.”