"takeoff" or "take-off"?

[nnc0]

Is there a definitive rule for the use of the word "takeoff" or "take-off" in the written form (SOPs or Supp Techniques or Abnormals)? Which version is correct?

In 20 yrs of writing them I'm always taken to task by those who think one or the other is the correct version but I can find a definitive reference source to resolve the question once and for all.

[keith williams]

Google is your friend. Do an internet search for something like Is take off one or two words?

If you do you will find several answer, but basically.

it is a single word when used as a noun, and it is two words when used as a verb.

But the various answer I found do appear to contradict slightly. Look it up.

[Equivocal]

If it helps, ICAO generally uses 'take-off' but sometimes drops the hyphen.. Don't think I've ever seen it as a single word in its documents.