Hero flounders badly, carrying unknown injury (6,8)
I believe the answer is:
frozen shoulder
'injury' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'hero flounders badly carrying unknown' is the wordplay.
'badly' indicates anagramming the letters.
'carrying' indicates putting letters inside.
'unknown' becomes 'z' (algebra).
'hero'+'flounders'='heroflounders'
'heroflounders' anagrammed gives 'froenshoulder'.
'froenshoulder' going around 'z' is 'FROZEN SHOULDER'.
Can you help me to learn more?
(Other definitions for frozen shoulder that I've seen before include "Getting alternative to fresh cut of meat" , "making it difficult to take up arms?" , "Perhaps extreme indifference" , "could be a pain" .)