First person to confront social worker is very determined (7)
I believe the answer is:
adamant
'very determined' is the definition.
(I've seen this in another clue)
'first person to confront social worker' is the wordplay.
'first' becomes 'a'.
'person' becomes 'D.A.' (D.A. is an example).
'to confront social' becomes 'm' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'worker' becomes 'ant' (worker is a type of ant).
'a'+'da'+'m'+'ant'='ADAMANT'
'is' is the link.
Can you help me to learn more?
(Other definitions for adamant that I've seen before include "intractable" , "Resolute; diamond (arch.)" , "unshakeable in purpose" , "Fabulous rock" , "Unswerving" .)