Child departs, giggling, scratching head (8)
I believe the answer is:
daughter
'child' is the definition.
(daughter is a kind of child)
'departs giggling scratching head' is the wordplay.
'departs' becomes 'd' (common abbreviation e.g. train timetables).
'giggling' becomes 'laughter'.
'scratching head' means to remove the first letter.
'laughter' with its initial letter removed is 'aughter'.
'd'+'aughter'='DAUGHTER'
(Other definitions for daughter that I've seen before include "'''Don't put your ... on the stage, Mrs Worthington'' (Noel Coward) (8)'" , "Female offspring" , "Girl" , "Close relative" , "The guard (anag.)" .)