Old boy with debts accepting five will be clear (7)
I believe the answer is:
obvious
'clear' is the definition.
('obvious' can be similar in meaning to 'clear')
'old boy with debts accepting five' is the wordplay.
'old boy' becomes 'ob'.
'with' says to put letters next to each other.
'debts' becomes 'ious'.
'accepting' means one lot of letters goes inside another.
'five' becomes 'v' ('V' can be a synonym of 'five').
'ob'+'ious'='obious'
'obious' placed around 'v' is 'OBVIOUS'.
'will be' is the link.
(Other definitions for obvious that I've seen before include "Easily perceived or understood" , "Clear as day" , "Quite evident, manifest" , "Evident, plain" , "Unmistakable" .)