Assistant turns up to indicate that they will give them the job (7)
I believe the answer is:
appoint
'they will give them the job' is the definition.
The definition suggests an adverb but the answer is not.
'assistant turns up to indicate' is the wordplay.
'assistant' becomes 'PA' (personal assistant).
'turns up' shows that the letters should be reversed in order.
'to indicate' becomes 'point' (synonyms).
'pa' reversed gives 'ap'.
'ap'+'point'='APPOINT'
'that' is the link.
Can you help me to learn more?
(Other definitions for appoint that I've seen before include "Put into a post" , "Fix" , "Give job to" , "Determine (a time/place)" , "Assign position to" .)