Fluid, for example, drained from phlegmy liquid (5)
I believe the answer is:
lymph
'fluid' is the definition.
(I know that lymph is a fluid)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for lymph that I've seen before include "Bodily fluid" , "discharge through wounds" , "Colourless fluid with white blood cells" , "Fluid associated with a gland" , "Body fluid" .)