1 C1 neutral
Of a jet engine or turbine, to increase rotational speed to reach full operating power
"The pilot waited for all four engines to fully spool up before requesting clearance for takeoff."
inseparable
spool up
C1 neutral separable transitive/intransitive
Of an engine, turbine, or system, to accelerate to operating speed; or to wind cable or thread onto a spool
In plain English
When a jet engine or machine speeds up to full power; or to wind something onto a reel
What does "spool up" mean?
3 meanings, ordered from most common to least. Color-coded by CEFR level.
2 B2 neutral
To wind cable, thread, or tape onto a spool
"He spooled up the fishing line neatly before storing the rod."
separable
3 C1 idiomatic informal
Informally, to prepare or get ready for something demanding
"The team needs a few days to spool up before tackling that project."
inseparable
Literal vs figurative
Words literally mean
To wind something upward onto a spool, or to accelerate like a spool winding — partially transparent
Actually means
When a jet engine or machine speeds up to full power; or to wind something onto a reel
Usage tip
Primarily technical aviation and engineering vocabulary. Commonly heard in cockpit communications and aerospace contexts. Also used in computing to describe initializing a system. The opposite is 'spool down.' Informally, 'spool up' is sometimes used metaphorically to mean getting ready or motivated.
Words that pair with "spool up"
Natural word combinations native speakers use most often.
engine turbine jet system process reactor
How to conjugate "spool up"
The five tense forms you'll use most often.
Base
spool up
I/you/we/they
3rd person
spools up
he/she/it
Past simple
spooled up
yesterday
Past participle
spooled up
have + pp
-ing form
spooling up
continuous
Hear "spool up" in the wild
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Other ways to say "spool up"
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