Consider a pool less than a mere (6)
I believe the answer is:
ponder
'consider' is the definition.
(thesaurus)
'a pool less than a mere' is the wordplay.
I cannot really understand how this works, but
'pool' could be 'pond' (synonyms) and 'pond' is found within the answer.
The remaining letters 'er' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for ponder that I've seen before include "Meditate, think deeply" , "Give thought to" , "Think carefully" , "4 down" , "Weigh in the mind" .)