One about to enter Iberian FC entrance (7)
I believe the answer is:
portico
'entrance' is the definition.
(thesaurus)
'one about to enter iberian fc' is the wordplay.
'one about' becomes 'ic' (I've seen this in other clues).
'to enter' is an insertion indicator.
'iberian fc' becomes 'porto' (FC Porto, Portuguese football team).
'ic' placed into 'porto' is 'PORTICO'.
(Other definitions for portico that I've seen before include "A number of columns" , "Covered porch with supporting columns" , "Colonnade, covered porch" , "covered area" , "Zeno's teaching colonnade" .)