Giant, athletic climber (8)
I believe the answer is:
monstera
'climber' is the definition.
The definition and answer can be both plants as well as being singular nouns.
Maybe there's an association between them I don't understand?
'giant athletic' is the wordplay.
'giant' becomes 'monster' (synonyms).
'athletic' becomes 'a' (this might be a standard abbreviation which I don't know about).
'monster'+'a'='MONSTERA'
Can you help me to learn more?
(Other definitions for monstera that I've seen before include "Swiss cheese" , "large plant" .)