Bill Nighy's beginning to divide current opinion (7)
I believe the answer is:
invoice
'bill' is the definition.
(I know that bill can be written as invoice)
'nighy's beginning to divide current opinion' is the wordplay.
'beginning to' indicates taking the first letters.
'divide' is an insertion indicator (inserted letters divide the word).
'current' becomes 'I' (physics symbol).
'opinion' becomes 'voice' (I've seen this in another clue).
The first letter of 'nighy' is 'n'.
'i'+'voice'='ivoice'
'n' put within 'ivoice' is 'INVOICE'.
(Other definitions for invoice that I've seen before include "Bill (fit to sing?)" , "ask for payment" , "Statement of sum due" , "Statement of account" , "Pollen holder" .)