If you need to type a tilde on a mac keyboard, you just need to press ‘Option’ ‘n’
This will give you this charachter: ~
NOTE: The ‘Option’ key on the mac keyboard is actually labelled ‘alt’. It has been a source of frustration for me that a company like Apple which prides itself on usabilty of its products would have such a quirk. I so often have to think when I see people write Option key and I look down and think is that the alt key or one of the other ones.
Tilde meaning
From Spanish tilde via the Latin titulus which means superscript.