Flabby and a bit wet, it clings to a rock (6)
I believe the answer is:
limpet
'it clings to a rock' is the definition.
The definition suggests a singular noun which matches the answer.
'flabby and a bit wet' is the wordplay.
'flabby' becomes 'limp' (I've seen this in another clue).
'and' says to put letters next to each other.
'a bit wet' becomes 'et' (I can't justify this - if you can you should believe this answer much more).
'limp'+'et'='LIMPET'
Can you help me to learn more?
(Other definitions for limpet that I've seen before include "Rockpool clinger?" , "sticker?" , "clingy type" , "Proverbially clinging shellfish" , "Marine mollusc" .)