Happy church always not quite crowded (8)
I believe the answer is:
Here is my best explanation:
'happy' is the definition.
('cheerful' can be similar in meaning to 'happy')
'church always not quite crowded' is the subsidiary indication.
'church' becomes 'ch' (common abbreviation).
'always' becomes 'eer' ('e'er' can be a synonym of 'always'**).
'not quite' means to remove the last letter.
'crowded' becomes 'full' ('full' can be similar in meaning to 'crowded').
'full' with its final letter removed is 'ful'.
(Other definitions for cheerful that I've seen before include "In good spirits, lighthearted", "Showing good spirits", "Lure chef into being in good spirits", "Contented", "Light-hearted", "Optimistic and upbeat", "Bright", "Jolly", "Upbeat" and "Genial".)