The word "secateurs" is missing from all English dictionaries except for US.

All the in title; the word "secateurs" appears as a spelling mistake when using any of the English dictionaries that are not the US dictionary. Specifically, I've been using the Australian one, but when I checked the other English options I found it was giving an error in British, Canada, New Zealand, and South Africa as well, but that it wasn't flagged as a mistake in US.

I don't understand how this would be missing?! It's in all the local Australian dictionaries (Collin, Macquarie) as well as Oxford, and it doesn't get flagged in Word's English(AU) dictionary either.

Genuinely baffled on this one! (also not sure how to add labels on this post sorry!!)