A second girl’s turned set on (8)
I believe the answer is:
assailed
'set on' is the definition.
The answer and definition are different parts of speech. However, adjectives and past participle verbs can sometimes define each other.
'a second girl's turned' is the wordplay.
'second' becomes 's' (common abbreviation).
'girl's turned' becomes 'sailed' (I can't justify this - if you can you should give a lot more credence to this answer).
'a'+'s'+'sailed'='ASSAILED'
Can you help me to learn more?
(Other definitions for assailed that I've seen before include "Under attack" , "became aggressive" , "charged" , "Attacked, lashed out" , "Set upon" .)