Clue: Haughty Louis IV moving forward — chasing fancy cup, sire? (12)
Answer: SUPERCILIOUS
Explanation: Definition: Haughty
A charade of SUPERCI, an anagram ('fancy') of 'cup sire', plus LIOUS, which is 'Louis' with the fourth letter moved up ~~one~~ ('IV moving forward'). 'Chasing' indicates the order of the particles.