# tightlock

> English word · Noun

## Definitions
1. A form of Janney coupler, typically used on North American mainline passenger rail cars, having mechanical features that reduce slack in normal operation and prevent telescoping in derailments, yet remain compatible with other Janney types.

## Etymology
From tight + lock.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/tightlock