This is usually Cer o 'ma in speech with the y elided.
Thank you :-)
Why is it not 'cer allan'?
That's "Go out" or "Get out". Cer o yma is "Go from here" or "Get out of here".
I'm sure that you're right (Tips does advise that, unlike English, prepositions are not always needed) but, if memory of my youth (a very, very long time ago!) serves people used to say Cer 'mas.
That's right. People in the south often say mas for "out" instead of allan, so you'll hear Cer mas! for "Go/Get out!".