He will have an inclination to be utterly determined (4-4)
I believe the answer is:
hell-bent
'utterly determined' is the definition.
(I know this)
'he will have an inclination' is the wordplay.
'will' becomes 'll' (contracted form, as in 'he'll' - 'he will').
'have' says to put letters next to each other.
'an inclination' becomes 'bent' (bent is a kind of inclination).
'he'+'ll'+'bent'='HELL-BENT'
'to be' is the link.
(Other definitions for hell-bent that I've seen before include "on path with good intentions" , "Determined at all costs" , "Absolutely determined" , "Dead set" , "Recklessly determined" .)