An interfering thread nut is a type of locknut

Locknut

A locknut, also known as a lock nut, locking nut, prevailing torque nut, stiff nut or elastic stop nut, is a nut that resists loosening under vibrations and torque. Elastic stop nuts and prevailing torque nuts are of the particular type where some portion of the nut deforms elastically to provide a...

 that has an over-sized root diameter. This creates an interference between the nut

Nut (hardware)

A nut is a type of hardware fastener with a threaded hole. Nuts are almost always used opposite a mating bolt to fasten a stack of parts together. The two partners are kept together by a combination of their threads' friction, a slight stretch of the bolt, and compression of the parts...

 and the fastener, plastically deforming the threads

Screw thread

A screw thread, often shortened to thread, is a helical structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the former being called a straight thread and the latter called a tapered thread...

 on the fastener. Due to this deformation they are usually only used on permanent or semi-permanent installations.

A variation of this nut is the tapered thread nut. It utilizes a tapered thread to achieve the interference. The nut goes on easily, because the thread diameter starts at a standard size; as the nut is further threaded on it begins to lock, much like a distorted thread locknut.