Thought the reed would flourish by the water (8)
I believe the answer is:
pondered
'thought' is the definition.
(pondering is a kind of thinking)
'reed would flourish by the water' is the wordplay.
'would' becomes 'd' (as in 'we'd' - 'we would').
'flourish' indicates an anagram (I've seen 'flourishing' mean this (letters grow or flourish differently)).
'by' says to put letters next to each other.
'the water' becomes 'pon' (I am not sure about this - if you are sure you should believe this answer much more).
'reed'+'d'='reedd'
'reedd' with letters rearranged gives 'dered'.
'dered' after 'pon' is 'PONDERED'.
'the' acts as a link.
Can you help me to learn more?
(Other definitions for pondered that I've seen before include "Cogitated" , "Gave thought to" , "Considered carefully" , "Mused" , "Contemplated deeply" .)