Half in boozer breaking taboo of some magnitude (3-4)
I believe the answer is:
non-zero
'half in boozer' is the definition.
The definition suggests an adjective which matches the answer.
'breaking taboo of some magnitude' is the wordplay.
'breaking' is an insertion indicator.
'taboo' becomes 'no-no' (I've seen this in another clue).
'of some' becomes 'ze' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'magnitude' becomes 'r' (r is a kind of magnitude).
'ze'+'r'='zer'
'nono' enclosing 'zer' is 'NON-ZERO'.
Can you help me to learn more?
(Other definitions for non-zero that I've seen before include "Having a positive or negative value, ie anything not equating to nought (mathematics)" , "Either positive or negative" .)