Otto's loaded, displaying capital (4)
I believe the answer is:
oslo
'capital' is the definition.
(capital of Norway)
'otto's loaded displaying' is the wordplay.
'displaying' indicates a hidden word.
'OSLO' is hidden in the letters of 'ottos loaded'.
(Other definitions for oslo that I've seen before include "Norwegian city, formerly Kristiania" , "Capital of Norway" , "Norway's capital city" , "It's capital in Anglos London" , "Capital often frozen" .)