Wreathed with flowers, a fish out of water? (9)
I believe the answer is:
'wreathed with flowers' is the definition.
(a garland is a floral wreath)
'a fish out of water?' is the wordplay.
'a fish' becomes 'gar' (gar is a kind of fish).
'out of water?' becomes 'landed' (I can't justify this - if you can you should believe this answer much more).
Can you help me to learn more?
(Other definitions for garlanded that I've seen before include "beset by flowers?" , "bays (around head)" , "Honoured" , "adorned with flowers" , "swathed in leaves" .)