Definition:Coordinate/Linguistic Note

Linguistic Note on Coordinate
It's an awkward word coordinate.

It really needs a hyphen in it to emphasise its pronunciation (loosely and commonly: coe-wordinate), and indeed, some authors spell it co-ordinate.

However, this makes it look unwieldy.

An older spelling puts a on the second "o": coördinate.

But this is considered archaic nowadays and few sources still use it.