Label whale starting from the rear flipper? (7)
I believe the answer is:
acrobat
'flipper?' is the definition.
(I've seen this in another clue)
'label whale starting from the rear' is the wordplay.
'label' becomes 'tab' (I've seen this in another clue).
'whale starting' becomes 'orca' (I can't explain this - if you can you should give a lot more credence to this answer).
'from the rear' says the letters should be written in reverse.
'tab'+'orca'='taborca'
'taborca' reversed gives 'ACROBAT'.
Can you help me to learn more?
(Other definitions for acrobat that I've seen before include "circus artiste" , "Performer going head over heels?" , "User of five ac" , "Gymnastic performer" , "flipper" .)