Special quality applied to boxer with a name like Primo Carnera? (7)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

IT (an undefinable “special quality”) + ALI (the boxer Muhammad Ali) + A + N (abbreviation for name). Primo Carnera was a 20th-century Italian heavyweight boxer, according to Wikipedia; I didn’t know that, but I’m really not into boxing.