Suspect party ultimately wild and extremely glitzy (5)
I believe the answer is:
dodgy
'suspect' is the definition.
(I've seen this before)
'party ultimately wild and extremely glitzy' is the wordplay.
'party' becomes 'do' (do can informally mean a party).
'ultimately' suggests the final letters.
'and' says to put letters next to each other.
'extremely' means to remove the middle letters (only the extremes of the word are used).
'glitzy' with its centre removed is 'gy'.
The last letter of 'wild' is 'd'.
'do'+'d'+'gy'='DODGY'
(Other definitions for dodgy that I've seen before include "fishy!" , "Dishonestly obtained" , "Disreputable" , "Not reliable (colloq.)" , "Unreliable" .)