Blubber — from whales, obviously (3)
I believe the answer is:
sob
'blubber' is the definition.
(I've seen this before)
'from whales obviously' is the wordplay.
'from' says the answer is hidden in the clue.
'SOB' is hidden in the letters of 'whales obviously'.
(Other definitions for sob that I've seen before include "Cry bitterly" , "Cry uncontrollably" , "Weep uncontrollably" , "Weep heavily, wail" , "Weep noisily" .)