Wine, beer and intially rum too - this means one's expecting the worst (3,5)
I believe the answer is:
red alert
'rum too this means one's expecting the worst' is the definition.
The definition suggests a singular noun which matches the answer.
'wine beer and intially' is the wordplay.
'wine' becomes 'red wine' (red is a type of wine).
'beer' becomes 'ale' (type of beer).
'and' means one lot of letters go next to another.
'intially' becomes 'rt' (I can't explain this - if you can you should give a lot more credence to this answer).
'red'+'ale'+'rt'='RED ALERT'
Can you help me to learn more?
(Other definitions for red alert that I've seen before include "State of high readiness" , "Severe warning" , "Severe 1 dn" , "Urgent warning" , "heightened security state" .)