# head of steam

> English word · Noun

## Definitions
1. A significant amount of energy, vigour or momentum, sufficient to make progress or succeed in a task.
2. Used other than figuratively or idiomatically: see head, steam.

## Etymology
The figurative sense is by metaphor from the literal one: the need of the boiler of a steam locomotive to exceed a minimum amount of pressure before the locomotive could start moving.

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