Home with jazzy style given huge architectural feature (8)
I believe the answer is:
intrados
'architectural feature' is the definition.
(term for part of an arch)
'home with jazzy style given huge' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'with' means one lot of letters go next to another.
'jazzy style' becomes 'trad' (trad is a style of jazz).
'given' says to put letters next to each other.
'huge' becomes 'os' (abbreviation for outsize).
'in'+'trad'+'os'='INTRADOS'
(Another definition for intrados that I've seen is " Under surface of arch".)