Clue: Attentive husband occasionally found out — slippery character to catch! (7)
Answer: HEEDFUL
Explanation: Definition: Attentive
A charade of H ('husband') plus EEDFUL, an envelope ('to catch') of DFU, an anagram ('out') of FUD ('occasionally **F**o**U**n*D')* in EEL ('slippery character').