Oh, just thought of another one, and I can't believe I haven't remembered it before now.
New-clee-ur. Not Nuke-U-lar.
Drives me up a wall. DH likes to say Nuke-u-lar. I correct him every time. And I've tried to teach the kids the right way to say it.
But, like 'definitely', just sound it out, for goodness sake.