Reptile climbing, say, with cold floor beneath (5)
I believe the answer is:
gecko
'reptile' is the definition.
(gecko is a kind of reptile)
'climbing say with cold floor beneath' is the wordplay.
'climbing say with' becomes 'ge' (I am not sure about this - if you are sure you should believe this answer much more).
'cold' becomes 'c' (eg on taps).
'floor' becomes 'ko' (I've seen this in other clues).
'beneath' is a charade indicator (letters next to each other) (in a down clue).
'ge'+'c'+'ko'='GECKO'
Can you help me to learn more?
(Other definitions for gecko that I've seen before include "Cold-blooded creature" , "Type of lizard" , "Thick-bodied lizard" , "Malaysian climber" , "Small lizard with adhesive foot-pads" .)