Ferdinand tense in dazzling display (4)
I believe the answer is:
riot
'dazzling display' is the definition.
(as in a riot of colour)
'ferdinand tense' is the wordplay.
'ferdinand' becomes 'rio' (I've seen this in other clues).
'tense' becomes 't' (abbreviation used in many dictionaries).
'rio'+'t'='RIOT'
'in' acts as a link.
(Other definitions for riot that I've seen before include "Affray, fighting in the streets" , "Unruly assembly" , "Debauchery" , "Violent crowd disturbance" , "Crowd violence" .)