Like some rocks beast knocked over by river (7)
I believe the answer is:
laminar
'like some rocks beast knocked over by river' is the definition.
I can't tell whether this defines the answer.
'beast knocked over by river' is the wordplay.
'beast' becomes 'animal' (a beast is an animal).
'knocked over' shows that the letters should be reversed in order.
'by river' becomes 'r' (abbreviation for river. I am not sure about the 'by' bit.).
'animal' reversed gives 'lamina'.
'lamina'+'r'='LAMINAR'
Can you help me to learn more?
(Other definitions for laminar that I've seen before include "Like streamlined flow" , "In sheet form" , "sheet upon sheet" , "Like smooth flows" , "Like some thin plates" .)