Definition of neckdown in US English:

neckdown

noun

North American
  • A reduction in width to a ‘neck’; something that narrows in this way, especially a section of a residential street that has been reduced in width as a means of traffic control.

Origin

1980s; earliest use found in Hot Rod. From neck + down, after to neck down, necked-down.

Pronunciation

neckdown

/ˈnɛkdaʊn/