Club youth leader's dramatic device (5)
I believe the answer is:
irony
'dramatic device' is the definition.
(I've seen this in another clue)
'club youth leader's' is the wordplay.
'club' becomes 'iron' (type of golf club).
'youth leader' becomes 'y' (I've seen this in other clues).
'iron'+'y'='IRONY'
(Other definitions for irony that I've seen before include "Use of words to convey the opposite of what they normally mean" , "Figure of speech" , "form of sarcasm" , "style of humour" , "Satire, sarcasm" .)