Clue: Dejected when damn rings puncture (7)
Answer: DEFLATE
Explanation: Definition: Dejected
FLAT (a puncture) "ringed by" DEE (i.e. D, euphemism for "damn"), though the definition surely points to DEFLATED. *Thanks to Dansar for the correction: it's FLAT (dejected) in DEE, with "puncture" as the definition.