Wave when tea's ready across lake? (8)
I believe the answer is:
flourish
'wave' is the definition.
(I know that wave can be written as flourish)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for flourish that I've seen before include "Prosper - display" , "success" , "Grow vigorously and healthily" , "Wax" , "Thrive; ornamental passage of music" .)