One so excessively dainty, as it were, should abandon airs (4)
I believe the answer is:
twee
'one so excessively dainty' is the definition.
I can't tell whether this definition defines the answer.
'as it were should abandon airs' is the wordplay.
'should abandon' is a deletion indicator.
'as'+'it'+'were'='asitwere'
'asitwere' with 'airs' taken out is 'TWEE'.
Can you help me to learn more?
(Other definitions for twee that I've seen before include "Attractively quaint" , "Mawkish" , "Sickly sweet" , "Small and sweet (colloq.)" , "Rather too pretty" .)