Giving cheer, Scooby-Doo gleefully lifted masks (8)

I believe the answer is:

feelgood

I'm a little stuck... Click here to teach me more about this clue!

'lifted masks' is the definition.
I know nothing about this answer so I can't tell whether this works.

'giving cheer scooby-doo gleefully' is the wordplay.
'FEELGOOD' is hidden back-to-front within the letters.
But, I'm unsure how the hidden word is indicated.

Can you help me to learn more?

Want a hint initially instead of a full solution? Install my app