Meaning and local context
In Newcastle, “mortal” means Very drunk. A common Newcastle nightlife meaning distinct from deadly.
Example in context
A local example is “He was mortal by midnight.” In plain English, that means “He was extremely drunk by midnight.”
He was mortal by midnight.
He was extremely drunk by midnight.
How to interpret it
The surrounding sentence is important when interpreting “mortal”. Use the regional sense above when the situation matches the example instead of relying on the word or phrase in isolation.
Tone and caution
The word concerns intoxication and can describe risky behaviour. Because this is informal regional language, tone and situation should guide whether you use “mortal” yourself or simply recognise it when someone else uses it.