Think about artificial lake with some hesitation (6)
I believe the answer is:
ponder
'think' is the definition.
(pondering is a kind of thinking)
'artificial lake with some hesitation' is the wordplay.
'artificial lake' becomes 'pond'.
'with' says to put letters next to each other.
'some hesitation' becomes 'er'.
'pond'+'er'='PONDER'
'about' acts as a link.
(Other definitions for ponder that I've seen before include "Contemplate, think over" , "Give thought to" , "Ruminate, mull over" , "Think deeply about, ruminate" , "Think carefully" .)