Alison ignoring boy when giving another name (5)
I believe the answer is:
alias
'another name' is the definition.
(I've seen this in another clue)
'alison ignoring boy when giving' is the wordplay.
'ignoring' suggests deleting specific letters.
'boy' becomes 'son' (synonyms).
'when giving' becomes 'as' (I can't justify this - if you can you should give a lot more credence to this answer).
'alison' with 'son' taken out is 'ali'.
'ali'+'as'='ALIAS'
Can you help me to learn more?
(Other definitions for alias that I've seen before include "False identity" , "stage name, perhaps" , "Cabbage salad" , "another name" , "Otherwise known as" .)