Dictionary.com
Thesaurus.com

cotter pin

American  

noun

Machinery.
  1. a cotter having a split end that is spread after being pushed through a hole to prevent it from working loose.


cotter pin British  

noun

  1. a split pin secured, after passing through holes in the parts to be attached, by spreading the ends

  2. a tapered pin threaded at the smaller end and secured by a nut after insertion

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of cotter pin

First recorded in 1890–95

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

At Tsurumi, outside Yokohama, another cotter pin evidently sheared off the wheel housing of a southbound freight car.

From Time Magazine Archive

Serial writers ran out of hazards years ago, have been working switches on them ever since; the loose cotter pin on the stagecoach, for example, has been used an estimated 7,000 times.

From Time Magazine Archive

The cause of the accident was narrowed down to a cotter pin, which one of the mechanics at Valbuena Field had forgotten to replace after greasing the landing wheels that morning.

From Time Magazine Archive

Release the cotter pin from the spindle nut, then remove the nut and washer, and the entire hub should slip off the axle.

From Time Magazine Archive

The washer F is held tightly against the hook by pressure from a spring, G. The spring is held in place by a small nut, H, and cotter pin, 1.

From The Boy Mechanic: Volume 1 700 Things for Boys to Do by Popular Mechanics Co.

Vocabulary.com logo
by dictionary.com

Dictionary.com's Learning Companion

Go beyond just looking up words.
Remember them forever with VocabTrainer.

Start training